pre-commit.tests: fix the eval

Without the fix the eval fails as:

    $ nix build --no-link -f. pre-commit.tests
    error:
       … while calling a functor (an attribute set with a '__functor' attribute)
         at lib/customisation.nix:304:7:
          303|     if missingArgs == { } then
          304|       makeOverridable f allArgs
             |       ^
          305|     # This needs to be an abort so it can't be caught with `builtins.tryEval`,

       … while evaluating a branch condition
         at lib/customisation.nix:171:7:
          170|       in
          171|       if isAttrs result then
             |       ^
          172|         result

       (stack trace truncated; use '--show-trace' to show the full, detailed trace)

       error: function 'anonymous lambda' called with unexpected argument 'git'
       at pkgs/by-name/pr/pre-commit/tests.nix:1:1:
            1| {
             | ^
            2|   gitMinimal,

0 files changed, 0 insertions, 0 deletions