Fix: corrected routing path for workers doc (#18224)

Closes: #17926

Author: kalikaruto

changelog.d/18224.doc

@@ -0,0 +1,2 @@
+Fixed a minor typo in the Synapse documentation.  
+Contributed by @karuto12.

docs/workers.md

@@ -255,7 +255,7 @@ information.
     ^/_matrix/client/(r0|v3|unstable)/keys/changes$
     ^/_matrix/client/(r0|v3|unstable)/keys/claim$
     ^/_matrix/client/(r0|v3|unstable)/room_keys/
-    ^/_matrix/client/(r0|v3|unstable)/keys/upload/
+    ^/_matrix/client/(r0|v3|unstable)/keys/upload$
 
     # Registration/login requests
     ^/_matrix/client/(api/v1|r0|v3|unstable)/login$