Bump to core-3.0.0, move to vitest, support ESM modules (#587)

vitest.config.ts

@@ -0,0 +1,21 @@
+import { defineConfig } from 'vitest/config'
+
+export default defineConfig({
+  test: {
+    globals: true,
+    environment: 'node',
+    include: ['**/*.test.ts'],
+    coverage: {
+      provider: 'v8',
+      reporter: ['text', 'lcov'],
+      include: ['src/**/*.ts'],
+      exclude: ['src/Globber.ts', 'src/Releases.ts'],
+      thresholds: {
+        lines: 100,
+        functions: 100,
+        branches: 95,
+        statements: 100,
+      },
+    },
+  },
+})