chore(cfnspec): update missing libraries to align with added eslint c…

…onfig

Latest spec update #7664 broke because the expectations are currently on the wrong file.
Additionally we're missing the exclude from `.npmignore`

packages/@aws-cdk/cfnspec/build-tools/create-missing-libraries.ts

@@ -229,6 +229,8 @@ async function main() {
       '*.tsbuildinfo',
       '',
       'tsconfig.json',
+      '',
+      '.eslintrc.js',
     ]);
 
     await write('lib/index.ts', [
@@ -264,7 +266,7 @@ async function main() {
       '```',
     ]);
 
-    await write('.eslintrc.json', [
+    await write('.eslintrc.js', [
       "const baseConfig = require('../../../tools/cdk-build-tools/config/eslintrc');",
       'module.exports = baseConfig;',
     ]);