python3Packages.pythonCatchConflictsHook: fix tests with lib.overrideDerivation

Use lib.overrideDerivation instead of <pkg>.overrideDerivation
to fix the evaluation of
python3Packages.pythonCatchConflictsHook.tests.catches-conflict-multiple-chains,
as buildPythonPackage and buildPythonApplication no longer provide
<pkg>.overrideDerivation

Clean up the leftover of commit 58bfe74123 ("buildPython*:
Deprecate and remove (buildPython* { ... }).override")

pkgs/development/interpreters/python/hooks/python-catch-conflicts-hook-tests.nix

@@ -1,4 +1,4 @@
-{ pythonOnBuildForHost, runCommand, writeShellScript, coreutils, gnugrep }: let
+{ lib, pythonOnBuildForHost, runCommand, writeShellScript, coreutils, gnugrep }: let
 
   pythonPkgs = pythonOnBuildForHost.pkgs;
 
@@ -38,7 +38,7 @@
   );
 
   # in order to test for a failing build, wrap it in a shell script
-  expectFailure = build: errorMsg: build.overrideDerivation (old: {
+  expectFailure = build: errorMsg: lib.overrideDerivation build (old: {
     builder = writeShellScript "test-for-failure" ''
       export PATH=${coreutils}/bin:${gnugrep}/bin:$PATH
       ${old.builder} "$@" > ./log 2>&1