Removed the checking for change fragment files from the test workflow

Details:

* Removed the checking for change fragment files from the test workflow.

* Updated the 'Making a change' section in the development docs accordingly.

* Note that the support for 'notshown' files is still needed (just undocumented
  now) because the 'make start' sequence needs to produce a dummy change so
  that the version start label is on a different commit than the release
  label of the previous release, which had been implemented with a 'notshown'
  (i.e. dummy) change fragment file.

Signed-off-by: Andreas Maier <maiera@de.ibm.com>

.github/workflows/test.yml

@@ -112,9 +112,6 @@ jobs:
       uses: actions/checkout@v4
       with:
         fetch-depth: 0
-    - name: Make sure this change adds or changes at least one change fragment file
-      run: |
-        bash -c "! git diff --exit-code origin/${{ github.base_ref }} changes/*.rst >/dev/null || (echo 'Please add or modify a change fragment file in the changes directory - for details read the Making a change section in the docs'; exit 1)"
     - name: Set up Python ${{ matrix.python-version }}
       uses: actions/setup-python@v5
       with:

changes/1573.notshown.rst

@@ -0,0 +1,2 @@
+Test: Removed the checking for change fragment files from the test workflow
+again.

docs/development.rst

@@ -636,12 +636,8 @@ For changes that have no corresponding issue:
 
     towncrier create noissue.<number>.<type>.rst --edit
 
-For changes where you do not want to create a change log entry:
-
-.. code-block:: sh
-
-    towncrier create noissue.<number>.notshown.rst --edit
-    # The file content will be ignored - it can also be empty
+For changes where you do not want to create or modify a change log entry,
+simply don't provide a change fragment file.
 
 where:
 
@@ -681,8 +677,6 @@ where:
     environment, that does not fix a bug and is not an enhanced functionality.
     This will show up in the "Cleanup" section of the change log.
 
-  - ``notshown`` - The change will not be shown in the change log.
-
 This command will create a new change fragment file in the ``changes``
 directory and will bring up your editor (usually vim).