Merge bitcoin/bitcoin#28347: lint: replace deprecated pkg_resources with importlib.metadata

6c008a2006 script: replace deprecated pkg_resources with importlib.metadata (Jon Atack)

Pull request description:

  Running our python linter with a recent python and the latest release of setuptools [v68.1.2](https://setuptools.pypa.io/en/stable/history.html):

  ```
  $ python3 --version
  Python 3.11.5
  $ ./test/lint/lint-python.py:12: DeprecationWarning: pkg_resources is deprecated as an API.
    See https://setuptools.pypa.io/en/latest/pkg_resources.html
    import pkg_resources
  ```

  Using `pkg_resources` was [deprecated](https://github.com/pypa/setuptools/pull/3843) earlier in [v67.5.0](https://setuptools.pypa.io/en/stable/history.html#id55): "Although pkg_resources has been discouraged for use, some projects still consider pkg_resources viable for usage. This change makes it clear that pkg_resources should not be used, emitting a DeprecationWarning when imported."

  The `importlib.metadata` library requires Python 3.8, which is currently our minimum-supported Python version.

  For more details about `importlib.metadata` and the two methods imported and used here, see:

  - https://docs.python.org/3/library/importlib.metadata.html
  - https://importlib-metadata.readthedocs.io/en/latest/api.html#importlib_metadata.metadata
  - https://importlib-metadata.readthedocs.io/en/latest/api.html#importlib_metadata.PackageNotFoundError

ACKs for top commit:
  MarcoFalke:
    lgtm ACK 6c008a2006 (review only, did not test)

Tree-SHA512: f5258d37043fcc9744f85641a60a3395ad43822c72d030dea8c39fa7f48ec3d7790cdeeb832f96e8f38046adb7c62fbc577c975ef0c77c8047c0c8f2353ce540

test/lint/lint-python.py

@@ -9,10 +9,12 @@ Check for specified flake8 and mypy warnings in python files.
 """
 
 import os
-import pkg_resources
 import subprocess
 import sys
 
+from importlib.metadata import metadata, PackageNotFoundError
+
+
 DEPS = ['flake8', 'lief', 'mypy', 'pyzmq']
 MYPY_CACHE_DIR = f"{os.getenv('BASE_ROOT_DIR', '')}/test/.mypy_cache"
 
@@ -99,10 +101,10 @@ ENABLED = (
 
 
 def check_dependencies():
-    working_set = {pkg.key for pkg in pkg_resources.working_set}
-
     for dep in DEPS:
-        if dep not in working_set:
+        try:
+            metadata(dep)
+        except PackageNotFoundError:
             print(f"Skipping Python linting since {dep} is not installed.")
             exit(0)