introduce install state v2 to replace v1

the v1 state is unnecessary since new repos are created for new additional_dependencies

pre_commit/repository.py

@@ -23,16 +23,20 @@ from pre_commit.util import rmtree
 logger = logging.getLogger('pre_commit')
 
 
+def _state_filename_v1(venv: str) -> str:
+    return os.path.join(venv, '.install_state_v1')
+
+
+def _state_filename_v2(venv: str) -> str:
+    return os.path.join(venv, '.install_state_v2')
+
+
 def _state(additional_deps: Sequence[str]) -> object:
     return {'additional_dependencies': sorted(additional_deps)}
 
 
-def _state_filename(venv: str) -> str:
-    return os.path.join(venv, f'.install_state_v{C.INSTALLED_STATE_VERSION}')
-
-
 def _read_state(venv: str) -> object | None:
-    filename = _state_filename(venv)
+    filename = _state_filename_v1(venv)
     if not os.path.exists(filename):
         return None
     else:
@@ -51,7 +55,10 @@ def _hook_installed(hook: Hook) -> bool:
         hook.language_version,
     )
     return (
-        _read_state(venv) == _state(hook.additional_dependencies) and
+        (
+            os.path.exists(_state_filename_v2(venv)) or
+            _read_state(venv) == _state(hook.additional_dependencies)
+        ) and
         not lang.health_check(hook.prefix, hook.language_version)
     )
 
@@ -87,14 +94,18 @@ def _hook_install(hook: Hook) -> None:
                 f'your environment\n\n'
                 f'more info:\n\n{health_error}',
             )
+
+        # TODO: remove v1 state writing, no longer needed after pre-commit 3.0
         # Write our state to indicate we're installed
-        state_filename = _state_filename(venv)
+        state_filename = _state_filename_v1(venv)
         staging = f'{state_filename}staging'
         with open(staging, 'w') as state_file:
             state_file.write(json.dumps(_state(hook.additional_dependencies)))
         # Move the file into place atomically to indicate we've installed
         os.replace(staging, state_filename)
 
+        open(_state_filename_v2(venv), 'a+').close()
+
 
 def _hook(
         *hook_dicts: dict[str, Any],