roachtest: reduce frequency of benchmark-only AC tests

These tests will only serve as coarse-grained benchmarks for things AC
cares about -- we don't need to run them nightly. They've spent ~2 weeks
through our nightly CI suite without flaking so reduce frequency to a
weekly cadence. We'll do this same thing for most tests added as part of
\#89208.

Release note: None

pkg/cmd/roachtest/tests/admission_control_elastic_backup.go

@@ -36,12 +36,9 @@ import (
 // in roachperf.
 func registerElasticControlForBackups(r registry.Registry) {
 	r.Add(registry.TestSpec{
-		Name:  "admission-control/elastic-backup",
-		Owner: registry.OwnerAdmissionControl,
-		// TODO(irfansharif): After two weeks of nightly baking time, reduce
-		// this to a weekly cadence. This is a long-running test and serves only
-		// as a coarse-grained benchmark.
-		// 	Tags:    []string{`weekly`},
+		Name:    "admission-control/elastic-backup",
+		Owner:   registry.OwnerAdmissionControl,
+		Tags:    []string{`weekly`},
 		Cluster: r.MakeClusterSpec(4, spec.CPU(8)),
 		Run: func(ctx context.Context, t test.Test, c cluster.Cluster) {
 			if c.Spec().NodeCount < 4 {

pkg/cmd/roachtest/tests/admission_control_elastic_cdc.go

@@ -29,12 +29,9 @@ import (
 // an increase in foreground latency.
 func registerElasticControlForCDC(r registry.Registry) {
 	r.Add(registry.TestSpec{
-		Name:  "admission-control/elastic-cdc",
-		Owner: registry.OwnerAdmissionControl,
-		// TODO(irfansharif): After two weeks of nightly baking time, reduce
-		// this to a weekly cadence. This is a long-running test and serves only
-		// as a coarse-grained benchmark.
-		// 	Tags:    []string{`weekly`},
+		Name:            "admission-control/elastic-cdc",
+		Owner:           registry.OwnerAdmissionControl,
+		Tags:            []string{`weekly`},
 		Cluster:         r.MakeClusterSpec(4, spec.CPU(8)),
 		RequiresLicense: true,
 		Run: func(ctx context.Context, t test.Test, c cluster.Cluster) {

pkg/cmd/roachtest/tests/admission_control_snapshot_overload.go

@@ -38,12 +38,9 @@ import (
 // make it shorter.
 func registerSnapshotOverload(r registry.Registry) {
 	r.Add(registry.TestSpec{
-		Name:  "admission-control/snapshot-overload",
-		Owner: registry.OwnerAdmissionControl,
-		// TODO(irfansharif): After two weeks of nightly baking time, reduce
-		// this to a weekly cadence. This is a long-running test and serves only
-		// as a coarse-grained benchmark.
-		// 	Tags:    []string{`weekly`},
+		Name:    "admission-control/snapshot-overload",
+		Owner:   registry.OwnerAdmissionControl,
+		Tags:    []string{`weekly`},
 		Cluster: r.MakeClusterSpec(4, spec.CPU(8)),
 		Run: func(ctx context.Context, t test.Test, c cluster.Cluster) {
 			if c.Spec().NodeCount < 4 {