unknown endpoints: allow PUT /_matrix/media/v3/upload

As of MSC2246 [1], the PUT method is allowed on the
/_matrix/media/v3/upload endpoint.

See the spec documentation here:
https://spec.matrix.org/v1.7/client-server-api/#put_matrixmediav3uploadservernamemediaid

[1]: matrix-org/matrix-spec-proposals#2246

Signed-off-by: Sumner Evans <[email protected]>

Author: sumnerevans

tests/unknown_endpoints_test.go

@@ -80,7 +80,5 @@ func TestUnknownEndpoints(t *testing.T) {
 		queryUnknownEndpoint(t, alice, []string{"_matrix", "media", "unknown"})
 		// v3 should exist, but not v3/unknown.
 		queryUnknownEndpoint(t, alice, []string{"_matrix", "media", "v3", "unknown"})
-
-		queryUnknownMethod(t, alice, "PUT", []string{"_matrix", "media", "v3", "upload"})
 	})
 }