python: Remove hacking dependency and use recent flake8.

The previously enabled 'hacking' checks were only applicable to Python 2
code.  OVS doesn't support Python 2 for a while now so it's fine to
remove the dependency on hacking.

TODO!

Without this, when using Python 3.12 and flake8 5.0.4, the following
errors are flagged:
  tests/check_acl_log.py:97:25: E231 missing whitespace after ':'
  tests/check_acl_log.py:102:71: E231 missing whitespace after ':'

This was reported and discussed in a couple of contexts:
https://mail.openvswitch.org/pipermail/ovs-dev/2023-November/409325.html
https://mail.openvswitch.org/pipermail/ovs-dev/2023-November/409277.html

And it's fixed in recent flake8/pycodestyle versions:
PyCQA/flake8#1845 (comment)

Signed-off-by: Dumitru Ceara <dceara@redhat.com>

.ci/linux-prepare.sh

@@ -23,7 +23,8 @@ cd ..
 #     https://github.com/pypa/pip/issues/10655
 pip3 install --disable-pip-version-check --user wheel
 pip3 install --disable-pip-version-check --user \
-    flake8 'hacking>=3.0' netaddr pyparsing sarif-tools sphinx setuptools
+    'flake8>=6.1.0' netaddr 'pycodestyle>=2.11' pyparsing sarif-tools \
+    sphinx setuptools
 
 # Install python test dependencies
 pip3 install -r python/test_requirements.txt

Documentation/intro/install/general.rst

@@ -176,10 +176,7 @@ following to obtain better warnings:
 
 - clang, version 3.4 or later
 
-- flake8 along with the hacking flake8 plugin (for Python code). The automatic
-  flake8 check that runs against Python code has some warnings enabled that
-  come from the "hacking" flake8 plugin. If it's not installed, the warnings
-  just won't occur until it's run on a system with "hacking" installed.
+- flake8 (for Python code)
 
 - the python packages listed in "python/test_requirements.txt" (compatible
   with pip). If they are installed, the pytest-based Python unit tests will

Makefile.am

@@ -402,16 +402,10 @@ ALL_LOCAL += flake8-check
 #   F811 redefinition of unused <name> from line <N> (only from flake8 v2.0)
 # D*** -- warnings from flake8-docstrings plugin
 # H*** -- warnings from flake8 hacking plugin (custom style checks beyond PEP8)
-#   H231 Python 3.x incompatible 'except x,y:' construct
-#   H232 Python 3.x incompatible octal 077 should be written as 0o77
-#   H233 Python 3.x incompatible use of print operator
-#   H238 old style class declaration, use new style (inherit from `object`)
-FLAKE8_SELECT = H231,H232,H233,H238
 FLAKE8_IGNORE = E121,E123,E125,E126,E127,E128,E129,E131,E203,E722,W503,W504,F811,D,H,I
 flake8-check: $(FLAKE8_PYFILES)
 	$(FLAKE8_WERROR)$(AM_V_GEN) \
 	  src='$^' && \
-	  flake8 $$src --select=$(FLAKE8_SELECT) $(FLAKE8_FLAGS) && \
 	  flake8 $$src --ignore=$(FLAKE8_IGNORE) $(FLAKE8_FLAGS) && \
 	  touch $@
 endif