mesa: enable texture floats only for drivers

To be on more safe side. This shouldn't matter theoretically as nothing in core
Mesa depends on them.

(cherry picked from commit 328bcdae25)

pkgs/development/libraries/mesa/default.nix

@@ -7,7 +7,7 @@
 , enableRadv ? false
 # Texture floats are patented, see docs/patents.txt, so we don't enable them for full Mesa.
 # It's overridden for mesa_drivers.
-, enableTextureFloats ? true
+, enableTextureFloats ? false
 , galliumDrivers ? null
 , driDrivers ? null
 , vulkanDrivers ? null

pkgs/top-level/all-packages.nix

@@ -8886,6 +8886,7 @@ with pkgs;
   mesa_drivers = mesaDarwinOr (
     let mo = mesa_noglu.override {
       grsecEnabled = config.grsecurity or false;
+      enableTextureFloats = true;
     };
     in mo.drivers
   );