ci: remove pylint and use ruff pylint rules instead

This replaces pylint with the ruff pylint rules for conventions (PLC),
errors (PLE), and warnings (PLW). The pylint refactoring rules (PLR)
were left out since they are extraneous, and as the name implies,
require heavy refactoring. See Ruff's pylint rules for more info. [1]

Also, bumped ruff version from 0.4.4 to 0.5.0

Refs:
[1] https://docs.astral.sh/ruff/rules/#pylint-pl

examples/lxd.py

@@ -197,8 +197,8 @@ def basic_lifecycle():
             print(inst.ephemeral)
             print(inst.state)
 
-            inst = lxd.get_instance(name)
-            inst.delete()
+            same_instance_retrieved = lxd.get_instance(name)
+            same_instance_retrieved.delete()
 
 
 def launch_virtual_machine():

pycloudlib/qemu/util.py

@@ -10,7 +10,7 @@
 
 def get_free_port():
     """Look for a free local port for SSHing to VM."""
-    global next_port  # pylint: disable=global-statement
+    global next_port  # noqa: PLW0603
     s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
     try:
         for port in range(next_port, next_port + 100):

pyproject.toml

@@ -48,6 +48,9 @@ docstring-code-format = true
 extend-select = [
   "D",   # pydocstyle
   "I",   # isort
+  "PLC",  # Pylint conventions
+  "PLE",  # Pylint errors
+  "PLW",  # Pylint warnings
 ]
 
 [tool.ruff.lint.pydocstyle]

tox.ini

@@ -1,14 +1,13 @@
 [tox]
 # As it may be undesired to make formatting changes, by default only check
-envlist = ruff, format-check, mypy, pylint, py38
+envlist = ruff, format-check, mypy, py38
 skipsdist = true
 
 [common]
 envdir = {toxworkdir}/.testenv
 deps =
     mypy==0.950
-    pylint==3.1.0
-    ruff==0.4.3
+    ruff==0.5.0
     types-mock==5.0.0
     types-pyyaml==6.0.12
     types-requests==2.31.0.6
@@ -51,11 +50,6 @@ envdir = {[common]envdir}
 deps = {[common]deps}
 commands = {envpython} -m ruff check -- pycloudlib examples setup.py
 
-[testenv:pylint]
-envdir = {[common]envdir}
-deps = {[common]deps}
-commands = {envpython} -m pylint --max-line-length=100 pycloudlib examples setup.py
-
 [testenv:format-check]
 envdir = {[common]envdir}
 deps = {[common]deps}
@@ -81,15 +75,9 @@ commands = sphinx-build -M html "." "_build" -W
 [tip]
 envdir = {toxworkdir}/.testenv-tip
 deps =
-    pylint
     ruff
     -rrequirements.txt
 
-[testenv:tip-pylint]
-envdir = {[tip]envdir}
-deps = {[tip]deps}
-commands = {envpython} -m pylint --max-line-length=100 pycloudlib examples setup.py
-
 [testenv:tip-ruff]
 envdir = {[tip]envdir}
 deps = {[tip]deps}