Conflicts between usepackage {inputenc} and {fontenc} by BibLateX

In previous questions (see Special character oe and BiblateX with XeLateX andProblem of compilation with XelateX (Package soul error), I presented my problem related to the taking into account of the special character oe by BibLateX in a Tufte-book documentclass. Actually, I just found the root of the problem, but don’t know how to fix it: the problem is solved when I delete the usepackage[T1]{fontenc}, which conflics with usepackage[utf8,french,latin9]{inputenc}.Unfortunately, I need to keep the inputenc package for formatting special characters for other functions (TikZ for example). How to modify the code so that BibLateX alone uses usepackage[T1]{fontenc}?

This is my code:

documentclass[nobib,twoside,symmetric,justified,marginals=raggedouter]{tufte-book}

usepackage{fontspec}
usepackage{fbb}

usepackage[utf8,french,latin9]{inputenc}% Required for including letters with accents
usepackage[T1]{fontenc}% Use 8-bit encoding that has 256 glyphs
usepackage[french]{babel}%.................. Language setup
addtocaptionsfrench{deftablename{Tableau}}
addtocaptionsfrench{deffigurename{Figure}}

usepackage{csquotes}
usepackage[backend=biber, style=authoryear-icomp]{biblatex}
makeatletter
newbibmacro*{adtcite}{%
  iffieldundef{shorthand}
    {ifthenelse{ifciteibidANDNOTiffirstonpage}
       {usebibmacro{cite:ibid}}
       {iffieldequals{namehash}{cbx@lasthash}
          {setunit{compcitedelim}}
          {printnames{labelname}%
           setunit*{printdelim{nameyeardelim}}%
           printlabeldateextra
           setunit*{printdelim{nametitledelim}}%
           savefield{namehash}{cbx@lasthash}}%
        usebibmacro{cite:title}}}%
    {usebibmacro{cite:shorthand}%
     usebibmacro{cite:reinit}}%
  setunit{multicitedelim}}
makeatother
newbibmacro*{cite:title}{%
  printtext[bibhyperref]{printfield[citetitle]{labeltitle}}}
DeclareCiteCommand{fadtcite}[mkbibfootnote]
  {usebibmacro{cite:init}%
   usebibmacro{prenote}}
  {usebibmacro{citeindex}%
   usebibmacro{adtcite}}
  {}
  {usebibmacro{cite:postnote}}
DeclareMultiCiteCommand{fadtcites}[mkbibfootnote]{fadtcite}{setunit{multicitedelim}}
DeclareAutoCiteCommand{fadt}{fadtcite}{fadtcites}
ExecuteBibliographyOptions{autocite=fadt}
usepackage{mdframed}
newmdenv[skipabove=3.5ex plus 1ex minus .2ex,% Equal to section title spacing
  innerleftmargin=0pt,innerrightmargin=0pt,%
  innerbottommargin=0pt,innertopmargin=0pt,linewidth=0pt,innermargin=0pt,%
  outermargin=dimexpr-marginparwidth-marginparseprelax]{mdfullwidth}
defbibenvironment{bibliography}
  {list{}{parsepbibparsep}}
  {endlist}
  {item}
AtEveryBibitem{hskip-bibhang}
begin{filecontents}{jobname.bib}
@BOOK{Buchet,
  author    = {Buchet, Edmond},
  title     = {Jean-S'{e}bastien Bach. L'oe uvre et la vie.
               Deux si`{e}cles d''{e}tudes et de t'{e}moignages},
  year      = {1963},
  publisher = {'{E}ditions Les Libraires Associ'{e}s},
  place     = {Saverne},
  pagetotal = {267},
}
end{filecontents}
addbibresource{jobname.bib}
PassOptionsToPackage{hyphens}{url}

begin{document}
frenchspacing
newthought{How to fix} the problem with "oe uvre"autocite[42]{Buchet}?

begin{fullwidth}
bibhang=0pt
printbibliography
end{fullwidth}
end{document}

documentclass[nobib,twoside,symmetric,justified,marginals=raggedouter]{tufte-book}

usepackage{fontspec}
%usepackage{fbb} <= DELETED

%usepackage[utf8,french,latin9]{inputenc}% <= DELETED
%usepackage[T1]{fontenc}% <= DELETED
usepackage[french]{babel}%.................. Language setup
addtocaptionsfrench{deftablename{Tableau}}
addtocaptionsfrench{deffigurename{Figure}}

usepackage{csquotes}
usepackage[backend=biber, style=authoryear-icomp]{biblatex}
makeatletter
newbibmacro*{adtcite}{%
  iffieldundef{shorthand}
    {ifthenelse{ifciteibidANDNOTiffirstonpage}
       {usebibmacro{cite:ibid}}
       {iffieldequals{namehash}{cbx@lasthash}
          {setunit{compcitedelim}}
          {printnames{labelname}%
           setunit*{printdelim{nameyeardelim}}%
           printlabeldateextra
           setunit*{printdelim{nametitledelim}}%
           savefield{namehash}{cbx@lasthash}}%
        usebibmacro{cite:title}}}%
    {usebibmacro{cite:shorthand}%
     usebibmacro{cite:reinit}}%
  setunit{multicitedelim}}
makeatother
newbibmacro*{cite:title}{%
  printtext[bibhyperref]{printfield[citetitle]{labeltitle}}}
DeclareCiteCommand{fadtcite}[mkbibfootnote]
  {usebibmacro{cite:init}%
   usebibmacro{prenote}}
  {usebibmacro{citeindex}%
   usebibmacro{adtcite}}
  {}
  {usebibmacro{cite:postnote}}
DeclareMultiCiteCommand{fadtcites}[mkbibfootnote]{fadtcite} 
   {setunit{multicitedelim}}
    DeclareAutoCiteCommand{fadt}{fadtcite}{fadtcites}
    ExecuteBibliographyOptions{autocite=fadt}
    usepackage{mdframed}
    newmdenv[skipabove=3.5ex plus 1ex minus .2ex,% Equal to section title spacing
      innerleftmargin=0pt,innerrightmargin=0pt,%
      innerbottommargin=0pt,innertopmargin=0pt,linewidth=0pt,innermargin=0pt,%
      outermargin=dimexpr-marginparwidth-marginparseprelax]{mdfullwidth}
    defbibenvironment{bibliography}
  {list{}{parsepbibparsep}}
  {endlist}
  {item}
AtEveryBibitem{hskip-bibhang}
begin{filecontents}{jobname.bib}
@BOOK{Buchet,
  author    = {Buchet, Edmond},
  title     = {Jean-Sébastien Bach. L'oe uvre et la vie.
               Deux siècles d'études et de témoignages},
  year      = {1963},
  publisher = {'{E}ditions Les Libraires Associés},
  place     = {Saverne},
  pagetotal = {267},
}
end{filecontents}
addbibresource{jobname.bib}
PassOptionsToPackage{hyphens}{url}

begin{document}
frenchspacing
newthought{How to fix} the problem with "oe uvre"autocite[42]{Buchet}?

begin{fullwidth}
bibhang=0pt
printbibliography
end{fullwidth}
end{document}