firefox: 73.0.1 -> 74.0 (#82276)

https://www.mozilla.org/en-US/firefox/74.0/releasenotes/

Co-authored-by: Daniel Frank <git@danielfrank.net>

pkgs/applications/networking/browsers/firefox/common.nix

@@ -94,11 +94,6 @@ stdenv.mkDerivation ({
   patches = [
     ./env_var_for_system_dir.patch
   ]
-  ++ lib.optional (lib.versionAtLeast ffversion "73") (fetchpatch {
-    # https://phabricator.services.mozilla.com/D60667
-    url = "https://hg.mozilla.org/mozilla-central/raw-rev/b3d8b08265b800165d684281d19ac845a8ff9a66";
-    sha256 = "0b4s75w7sl619rglcjmlyvyibpj2ar5cpy6pnywl1xpd9qzyb27p";
-  })
   ++ patches;
 
 
@@ -297,6 +292,9 @@ stdenv.mkDerivation ({
     inherit browserName;
   } // lib.optionalAttrs gtk3Support { inherit gtk3; };
 } //
+lib.optionalAttrs (lib.versionAtLeast ffversion "74") {
+  hardeningDisable = [ "format" ]; # -Werror=format-security
+} //
 # the build system verifies checksums of the bundled rust sources
 # ./third_party/rust is be patched by our libtool fixup code in stdenv
 # unfortunately we can't just set this to `false` when we do not want it.