Test enable groups as specified by PR labels (#2357)

* Allow CIBW_ENABLE to control the wheels built in testing

* Set CIBW_ENABLE using PR labels

* Add docs

* Build everything on the main branch

* Add CIBW_ENABLE=all option

This was mostly for use in the `main` building case, because otherwise it's maybe a bit too easy to forget to update this file when adding an enable group

* Remove dead code

* Make unit tests robust to the value of CIBW_ENABLE

* Fix tests that explicitly choose pypy

* Fix test expectation

* Don't expect impossible wheels in expected_wheels

* Simplify logic in expected_wheels

* CircleCI- run with CIBW_ENABLE=all only on the main branch

* Azure pipelines - run with CIBW_ENABLE=all on main branch

* Update gitlab to run CIBW_ENABLE=all on main

* Set CIBW_ENABLE=all on travis - it only runs on main anyway

* Fix job name error on CircleCI

* Fix tests for graalpy

* Update the test configuration to use the label

* Remove duplication of default value. Make it affect sample build too

* Move the action to after deps are installed

* GraalPy workaround for this assumption

* Make unit test resilient to changing CIBW_ENABLE

cibuildwheel/options.py

@@ -634,8 +634,10 @@ class Options:
             "enable", env_plat=False, option_format=ListFormat(sep=" "), env_rule=InheritRule.APPEND
         )
         try:
-            enable = {EnableGroup(group) for group in enable_groups.split()}
-            enable.update(EnableGroup(command_line_group) for command_line_group in args.enable)
+            enable = {
+                *EnableGroup.parse_option_value(enable_groups),
+                *EnableGroup.parse_option_value(" ".join(args.enable)),
+            }
         except ValueError as e:
             msg = f"Failed to parse enable group. {e}. Valid group names are: {', '.join(g.value for g in EnableGroup)}"
             raise errors.ConfigurationError(msg) from e