Improve pre-commit workflow (#2602)

* feat: add `isort` to `pre-commit`

* ci: skip `__init__.py` file for `isort`

* ci: make `isort` mandatory in lint pipeline

* docs: add a section on Git hooks

* ci: check isort diff

* fix: isort from master branch

* docs: add pre-commit badge

* ci: update black + bandit versions

* feat: add PR template

* refactor: PR template

* ci: remove bandit

* docs: add Black badge

* ci: try to remove all `|| true` statements

* ci: remove lint_python job

- Remove `lint_python` CI job
- Move `pyupgrade` job to `pre-commit` workflow

* fix: avoid messing with typing

* docs: add a note on running `pre-cpmmit` manually

* ci: apply `pre-commit` to the whole codebase

tests/vector/utils.py

@@ -1,10 +1,10 @@
+import time
 from typing import Optional
 
 import numpy as np
-import gym
-import time
 
-from gym.spaces import Box, Discrete, MultiDiscrete, MultiBinary, Tuple, Dict
+import gym
+from gym.spaces import Box, Dict, Discrete, MultiBinary, MultiDiscrete, Tuple
 
 spaces = [
     Box(low=np.array(-1.0), high=np.array(1.0), dtype=np.float64),