add config file for pre-commit hooks framework

pre-commit helps managing and maintaining multi-language pre-commit hooks.
This commit adds a pre-commit configuration to run a certian version of
clang-format utility. Later we can add sections for other languages as
well. pre-commit developers also provide the CI system which uses the
same config file.

https://pre-commit.com/
https://pre-commit.ci/

Reviewed-by: Saša Nedvědický <sashan@openssl.org>
Reviewed-by: Neil Horman <nhorman@openssl.org>
(Merged from openssl#28436)

Author: quarckster

.pre-commit-config.yml

@@ -0,0 +1,8 @@
+ci:
+  autofix_prs: false
+repos:
+  - repo: "https://github.com/pre-commit/mirrors-clang-format"
+    rev: "v21.1.0"
+    hooks:
+    - id: "clang-format"
+      types_or: ["c"]