heptapod-ci: remove push exception for named branches The internal workings of Heptapod cause even fast-forward merges to look like pushes to Gitlab. The only way to run a pipeline on topic-less named branches is not through the web interface. I am probably the only person affected by this, so it's not really a problem. This was confirmed with Georges, the maintainer of Heptapod, though the only way to be *actually* sure, is to merge this and see.

heptapod-ci: (hopefully) fix the pipeline savings system There is no easy way for me to test this outside of the actual repo since it would require setting up `heptapod-runner` locally, making a Git repo with the right changes, etc. It's not worth my time at this point. If this fails, I'll try to ask for help from Georges, the maintainer of Heptapod.

heptapod-ci: don't run pipelines for topic-less branches See inline comment for more details.

clonebundles: add warning if auto-generate is enabled without formats

clonebundles: fix display of auto-generate.on-change lines

hgweb: drop references to deprecated cgitb cgitb is going away and gives warnings when importing, and that make tests fail: $TESTTMP/hgweb.cgi:5: DeprecationWarning: 'cgitb' is deprecated and slated for removal in Python 3.13 The lack of a "nice" high level error handler is not a huge problem, neither for users (where it is disabled anyway) or for tests (where we don't use a browser and the plain tracebacks often are more readable). It is inevitable that it is going away, and there is no obvious alternative. Remove it and move on.