Adjust publish action to allow PyPI to be skipped on experimental rel…

…eases

.github/workflows/pyrealm_publish.yaml

@@ -76,13 +76,15 @@ jobs:
           repository-url: https://test.pypi.org/legacy/
           # skip-existing: true
 
-  # The final job in the workflow is to publish to the real PyPI
+  # The final job in the workflow is to publish to the real PyPI as long as the release
+  # name does not contain the tag 'test-pypi-only'
   publish-PyPI:
     needs: publish-TestPyPI
     name: Publish pyrealm to PyPI
     runs-on: ubuntu-latest
     permissions:
       id-token: write
+    if: ${{ ! contains('test-pypi-only', github.event.release.name)}}
 
     steps:
       # Download the built package files from the job artifacts

docs/source/development/release_process.md

@@ -90,6 +90,11 @@ a target branch. The steps are:
    * Alternatively, you can simply type the tag name into that drop down and the tag
      will be created alongside the draft release.
 
+1. You will need to choose a title for the release: basically `Release vX.Y.Z` is fine.
+   However, the title text also provides a mechanism for suppressing automatic trusted
+   publication to the main PyPI server by using `Release vX.Y.Z test-pypi-only`. See
+   below for details.
+
 1. You can create release notes automatically - this is basically a list of the commits
    being added since the last release - and can also set the version as a pre-release.
    This is different from having an explicit release version number (e.g. `X.Y.Za1`) -
@@ -177,6 +182,11 @@ basic flow is:
 1. As long as all the steps above succeed, the job artefacts are now published to the
    main PyPI site, which is also configured to trust publications from the repository.
 
+   The last step of publication to the main PyPI site can be skipped by including the
+   text `test-pypi-only` in the title text for the release. This allows pre-release
+   tests and experimentation to be tested without automatically adding them to the
+   official released versions.
+
 ```{eval-rst}
 .. include::  ../../../.github/workflows/pyrealm_publish.yaml
     :code: yaml