Docs: Add EXCLUDE_PROJECTS option to update-plugin-list.py (pytes…

…t-dev#12901)

This allows to exclude specified packages from being listed on the
Pytest Plugin List [1] page.

[1] https://docs.pytest.org/en/latest/reference/plugin_list.html

changelog/12901.doc.rst

@@ -0,0 +1 @@
+Improved ``update-plugin-list.py`` program by adding ``EXCLUDE_PROJECTS`` mechanism

scripts/update-plugin-list.py

@@ -68,6 +68,7 @@
     "flask_fixture",
     "databricks-labs-pytester",
 }
+EXCLUDE_PROJECTS: set[str] = set()
 
 
 def escape_rst(text: str) -> str:
@@ -116,6 +117,7 @@ def pytest_plugin_projects_from_pypi(session: CachedSession) -> dict[str, int]:
         if (
             (name := p["name"]).startswith(("pytest-", "pytest_"))
             or name in ADDITIONAL_PROJECTS
+            and name not in EXCLUDE_PROJECTS
         )
     }