Migrate to ESM and upgrade dependencies (#1330)

* Migrate to ESM and upgrade dependencies

* Add ESM migration note to README for V7

* Remove unnecessary devDependencies: ts-node, @types/jest

* npm audit fix

* Upgrade @types/node to version 26.0.0

* Clarify ESM migration details in README for V7

* Update README and dependencies

* Fix lint issue

jest.config.ts

@@ -0,0 +1,24 @@
+export default {
+  clearMocks: true,
+  moduleFileExtensions: ['js', 'ts'],
+  roots: ['<rootDir>'],
+  testEnvironment: 'node',
+  testMatch: ['**/*.test.ts'],
+  transform: {
+    '^.+\\.ts$': [
+      'ts-jest',
+      {
+        useESM: true,
+        diagnostics: {
+          ignoreCodes: [151002]
+        }
+      }
+    ]
+  },
+  extensionsToTreatAsEsm: ['.ts'],
+  transformIgnorePatterns: ['node_modules/(?!(@actions)/)'],
+  moduleNameMapper: {
+    '^(\\.{1,2}/.*)\\.js$': '$1'
+  },
+  verbose: true
+}