feat: migrate to ESM and update dependencies (#949)

* feat: migrate to ESM and update dependencies

- Migrated the project to ESM to support the latest `@actions/*` package versions.
- Updated dependencies to their latest versions, including `@actions/core`, `@actions/github`, and others.
- Replaced `.prettierrc.js` with `.prettierrc.json` for configuration.
- Updated ESLint configuration to use ESM and added new rules.
- Refactored test files to use `jest` with ESM imports.
- Removed deprecated files and updated import paths to use `.js` extensions.
- Added new files for improved configuration and removed unnecessary mocks.
- Updated README to reflect breaking changes in version 7.

* docs: update README to clarify ESM migration details and adjust TypeScript configuration

jest.config.ts

@@ -0,0 +1,23 @@
+export default {
+  clearMocks: true,
+  moduleFileExtensions: ['js', 'ts'],
+  testEnvironment: 'node',
+  testMatch: ['**/*.test.ts'],
+  transform: {
+    '^.+\\.ts$': [
+      'ts-jest',
+      {
+        useESM: true,
+        diagnostics: {
+          ignoreCodes: [151002]
+        }
+      }
+    ]
+  },
+  extensionsToTreatAsEsm: ['.ts'],
+  transformIgnorePatterns: ['node_modules/(?!(@actions|@octokit)/)'],
+  moduleNameMapper: {
+    '^(\\.{1,2}/.*)\\.js$': '$1'
+  },
+  verbose: true
+}