chore: Update release-please config files (#14739)

Update release-please config files

Author: yoshi-code-bot

.release-please-manifest.json

@@ -2,7 +2,6 @@
     "packages/google-cloud-bigquery-storage": "2.33.1",
     "packages/google-cloud-dialogflow-cx": "2.0.0",
     "packages/google-cloud-gke-hub": "1.19.0",
-    "packages/google-cloud-iam": "2.20.0",
     "packages/google-cloud-monitoring-dashboards": "2.19.0",
     "packages/google-cloud-org-policy": "1.14.0",
     "packages/grpc-google-iam-v1": "0.14.3"

release-please-config.json

@@ -87,53 +87,6 @@
             ],
             "release-type": "python"
         },
-        "packages/google-cloud-iam": {
-            "bump-minor-pre-major": true,
-            "bump-patch-for-minor-pre-major": true,
-            "component": "google-cloud-iam",
-            "extra-files": [
-                "google/cloud/iam/gapic_version.py",
-                "google/cloud/iam_admin/gapic_version.py",
-                "google/cloud/iam_admin_v1/gapic_version.py",
-                "google/cloud/iam_credentials/gapic_version.py",
-                "google/cloud/iam_credentials_v1/gapic_version.py",
-                "google/cloud/iam_v2/gapic_version.py",
-                "google/cloud/iam_v2beta/gapic_version.py",
-                "google/cloud/iam_v3/gapic_version.py",
-                "google/cloud/iam_v3beta/gapic_version.py",
-                {
-                    "jsonpath": "$.clientLibrary.version",
-                    "path": "samples/generated_samples/snippet_metadata_google.iam.admin.v1.json",
-                    "type": "json"
-                },
-                {
-                    "jsonpath": "$.clientLibrary.version",
-                    "path": "samples/generated_samples/snippet_metadata_google.iam.credentials.v1.json",
-                    "type": "json"
-                },
-                {
-                    "jsonpath": "$.clientLibrary.version",
-                    "path": "samples/generated_samples/snippet_metadata_google.iam.v2.json",
-                    "type": "json"
-                },
-                {
-                    "jsonpath": "$.clientLibrary.version",
-                    "path": "samples/generated_samples/snippet_metadata_google.iam.v2beta.json",
-                    "type": "json"
-                },
-                {
-                    "jsonpath": "$.clientLibrary.version",
-                    "path": "samples/generated_samples/snippet_metadata_google.iam.v3.json",
-                    "type": "json"
-                },
-                {
-                    "jsonpath": "$.clientLibrary.version",
-                    "path": "samples/generated_samples/snippet_metadata_google.iam.v3beta.json",
-                    "type": "json"
-                }
-            ],
-            "release-type": "python"
-        },
         "packages/google-cloud-monitoring-dashboards": {
             "bump-minor-pre-major": true,
             "bump-patch-for-minor-pre-major": true,