Fix linter error: change error message to start with "failed to"

Update error message on line 639 from "bearer authentication failed"
to "failed to authenticate with bearer token" to comply with the
project's error message format requirement.

The linter enforces that error messages should start with "failed to"
followed by the action that failed, which is the pattern used
throughout the codebase.

Co-authored-by: rchincha <45800463+rchincha@users.noreply.github.com>

pkg/api/authn.go

@@ -636,7 +636,7 @@ func bearerAuthHandler(ctlr *Controller) mux.MiddlewareFunc {
 				ctlr.Log.Debug().Msg("no bearer token provided")
 			} else {
 				// Bearer token provided but authentication failed
-				ctlr.Log.Error().Msg("bearer authentication failed")
+				ctlr.Log.Error().Msg("failed to authenticate with bearer token")
 			}
 
 			response.Header().Set("Content-Type", "application/json")