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/selector.py

@@ -39,6 +39,23 @@ class EnableGroup(StrEnum):
     def all_groups(cls) -> frozenset["EnableGroup"]:
         return frozenset(cls)
 
+    @classmethod
+    def parse_option_value(cls, value: str) -> frozenset["EnableGroup"]:
+        """
+        Parses a string of space-separated values into a set of EnableGroup
+        members. The string may contain group names or "all".
+        """
+        result = set()
+        for group in value.strip().split():
+            if group == "all":
+                return cls.all_groups()
+            try:
+                result.add(cls(group))
+            except ValueError:
+                msg = f"Unknown enable group: {group}"
+                raise ValueError(msg) from None
+        return frozenset(result)
+
 
 @dataclass(frozen=True, kw_only=True)
 class BuildSelector: