[PR #9972/9916d329 backport][3.11] Revert "Only construct the allowed_methods set once for a StaticResource" (#9973)

Co-authored-by: J. Nick Koston <[email protected]>

Author: patchback[bot]

CHANGES/9972.bugfix.rst

@@ -0,0 +1,3 @@
+Reverted an optimization to avoid rebuilding the allowed methods for ``StaticResource`` on every request -- by :user:`bdraco`.
+
+``aiohttp-cors`` needs to be able to modify the allowed methods at run time via this internal.

aiohttp/web_urldispatcher.py

@@ -580,7 +580,6 @@ def __init__(
                 "HEAD", self._handle, self, expect_handler=expect_handler
             ),
         }
-        self._allowed_methods = set(self._routes)
 
     def url_for(  # type: ignore[override]
         self,
@@ -650,7 +649,7 @@ async def resolve(self, request: Request) -> _Resolve:
         if not path.startswith(self._prefix2) and path != self._prefix:
             return None, set()
 
-        allowed_methods = self._allowed_methods
+        allowed_methods = set(self._routes)
         if method not in allowed_methods:
             return None, allowed_methods