env_select: ignore other env configurations when provisioning

When running provision, ignore other environments, since their configuration
might not be valid until running in the provisioned environment.

Fix #2862

Author: masenf

src/tox/session/env_select.py

@@ -242,6 +242,10 @@ def _finalize_config(self) -> None:
 
     def _build_run_env(self, name: str) -> RunToxEnv | None:
         if self._provision is not None and self._provision[0] is False and name == self._provision[1]:
+            # ignore provision env unless this is a provision run
+            return None
+        if self._provision is not None and self._provision[0] and name != self._provision[1]:
+            # ignore other envs when this is a provision run
             return None
         env_conf = self._state.conf.get_env(name, package=False)
         if self._provision is not None and self._provision[1] == name: