🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

Author: gcf-owl-bot[bot]

core/common/.mocharc.js

@@ -0,0 +1,29 @@
+// Copyright 2026 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+const config = {
+  "enable-source-maps": true,
+  "throw-deprecation": true,
+  "timeout": 10000,
+  "recursive": true
+}
+if (process.env.MOCHA_THROW_DEPRECATION === 'false') {
+  delete config['throw-deprecation'];
+}
+if (process.env.MOCHA_REPORTER) {
+  config.reporter = process.env.MOCHA_REPORTER;
+}
+if (process.env.MOCHA_REPORTER_OUTPUT) {
+  config['reporter-option'] = `output=${process.env.MOCHA_REPORTER_OUTPUT}`;
+}
+module.exports = config

core/common/.nycrc

@@ -0,0 +1,24 @@
+{
+  "report-dir": "./.coverage",
+  "reporter": ["text", "lcov"],
+  "exclude": [
+    "**/*-test",
+    "**/.coverage",
+    "**/apis",
+    "**/benchmark",
+    "**/conformance",
+    "**/docs",
+    "**/samples",
+    "**/scripts",
+    "**/protos",
+    "**/test",
+    "**/*.d.ts",
+    ".jsdoc.js",
+    "**/.jsdoc.js",
+    "karma.conf.js",
+    "webpack-tests.config.js",
+    "webpack.config.js"
+  ],
+  "exclude-after-remap": false,
+  "all": true
+}