internal/task: skip updating x/exp/event dep in x/pkgsite-metrics

For golang/go#73264.
For golang/go#74596.

Change-Id: I765584a114f835a2c1bdceb9d976c97077b16218
Reviewed-on: https://go-review.googlesource.com/c/build/+/698535
Auto-Submit: Dmitri Shuralyov <dmitshur@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Carlos Amedee <carlos@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
diff --git a/internal/task/tagx.go b/internal/task/tagx.go
index e2c9150..047bf60 100644
--- a/internal/task/tagx.go
+++ b/internal/task/tagx.go
@@ -199,6 +199,15 @@
 		if !x.considerModuleForAutomaticUpdate(req.Mod.Path) {
 			continue
 		}
+		if project == "pkgsite-metrics" && req.Mod.Path == "golang.org/x/exp/event" {
+			// The golang.org/x/exp/event dependency is updated as far as it can be
+			// in CL 697176, and further updates require adapting to upstream API changes.
+			// Automatically updating this dependency won't work until this is resolved,
+			// so skip it.
+			//
+			// TODO(go.dev/issue/74596): Delete this skip after the repository is updated.
+			continue
+		}
 		wait := true
 		if !isXRoot(req.Mod.Path) {
 			ctx.Printf("not waiting on %v's requirement on %v: not a golang.org/x root module", project, req.Mod.Path)