Add pre-commit

As a starting point for the code renovation it makes sense to add
pre-commit with the same configuration as we spread across the other
services. For now comment out hooks that fail and address them one by
one.
At the end of the series we would have pre-commit executing all the
necessary checks (linting, flake, black, mypy, etc) and it will be
invoked directly in the `tox -e pep8` to unify all the processing. We
are going to re-format source code with `black` adding revisions to
git blame ignore to reduce amount of noise. This will help us to have
reasonable formatting of the code with possibility to just auto-format
the code.

Change-Id: Ia00f4209cde8f64828dc2d827d49bfc4bd6c1efa

.pre-commit-config.yaml

@@ -0,0 +1,46 @@
+---
+default_language_version:
+  # force all unspecified python hooks to run python3
+  python: python3
+repos:
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v4.6.0
+    hooks:
+      - id: trailing-whitespace
+      - id: mixed-line-ending
+        args: ['--fix', 'lf']
+        exclude: '.*\.(svg)$'
+      - id: check-byte-order-marker
+      - id: check-executables-have-shebangs
+      - id: check-merge-conflict
+      - id: debug-statements
+      - id: check-yaml
+        files: .*\.(yaml|yml)$
+        exclude: '^zuul.d/.*$'
+  # TODO(gtema): Uncomment once content is fixed
+  # - repo: https://github.com/PyCQA/doc8
+  #   rev: v1.1.1
+  #   hooks:
+  #     - id: doc8
+  # - repo: https://github.com/asottile/pyupgrade
+  #   rev: v3.15.2
+  #   hooks:
+  #     - id: pyupgrade
+  #       args: ['--py38-plus']
+  # TODO(gtema): Uncomment it once all files are blackified
+  # - repo: https://github.com/psf/black
+  #   rev: 24.4.0
+  #   hooks:
+  #     - id: black
+  #       args: ['-S', '-l', '79']
+  # - repo: https://opendev.org/openstack/hacking
+  #   rev: 6.1.0
+  #   hooks:
+  #     - id: hacking
+  #       additional_dependencies:
+  #         - flake8-import-order~=0.18.2
+  #       exclude: '^(doc|releasenotes|tools)/.*$'
+  # - repo: https://github.com/pre-commit/mirrors-mypy
+  #   rev: v1.9.0
+  #   hooks:
+  #     - id: mypy