Remove unused .pre-commit-config.yaml (#1042)

Since we don't use that tool (<https://pre-commit.com>), and there are
better alternatives should we want to expand coverage of these kind of
things.

Closes @W-7923935@.

[skip changelog]

.pre-commit-config.yaml

@@ -1,7 +0,0 @@
-repos:
--   repo: https://github.com/pre-commit/pre-commit-hooks
-    rev: v2.3.0
-    hooks:
-    -   id: check-yaml
-    -   id: end-of-file-fixer
-    -   id: trailing-whitespace