mesa: don't depend on build python

`mesa-overlay-control.py` has build python in it's shebang

`pkgsCross.aarch64-multiplatform.sway`

pkgs/development/libraries/mesa/default.nix

@@ -223,6 +223,7 @@ self = stdenv.mkDerivation {
     libffi libvdpau libelf libXvMC
     libpthreadstubs openssl /*or another sha1 provider*/
     zstd libunwind
+    python3Packages.python # for shebang
   ] ++ lib.optionals haveWayland [ wayland wayland-protocols ]
     ++ lib.optionals stdenv.isLinux [ libomxil-bellagio libva-minimal udev lm_sensors ]
     ++ lib.optionals enableOpenCL [ libclc llvmPackages.clang llvmPackages.clang-unwrapped rustc rust-bindgen' spirv-llvm-translator' ]
@@ -320,6 +321,9 @@ self = stdenv.mkDerivation {
       fi
     done
 
+    # Don't depend on build python
+    patchShebangs --host --update $out/bin/*
+
     # NAR doesn't support hard links, so convert them to symlinks to save space.
     jdupes --hard-links --link-soft --recurse "$drivers"