Get rid of CommonJS dependency

Use dynamic imports, even though Vite does not quite yet support this
for node_modules. See vitejs/vite#14102

Tried different approaches, including `import.meta.glob` to get all the
locale names first. But the static analysis still can't figure out all
the possible imports, so I get the dreaded warning.

package.json

@@ -5,7 +5,7 @@
   "type": "module",
   "scripts": {
     "dev": "vite",
-    "build": "tsc && vite build",
+    "build": "tsc && vite build && mkdir -p dist/node_modules/dayjs/esm && cp -r node_modules/dayjs/esm/locale dist/node_modules/dayjs/esm/",
     "lint": "eslint . --ext ts,tsx --report-unused-disable-directives --max-warnings 0",
     "preview": "vite preview"
   },
@@ -45,7 +45,6 @@
     "prettier": "^3.3.2",
     "typescript": "^5.2.2",
     "vite": "^5.2.0",
-    "vite-plugin-commonjs": "^0.10.1",
     "vite-plugin-dynamic-import": "^1.5.0",
     "vite-plugin-i18next-loader": "^2.0.12"
   }

src/config/i18n.js

@@ -35,7 +35,9 @@ export function getPartiallySupportedLocales() {
 }
 
 export function handleLanguageChange( newLanguage, firstDayOfWeek = 1 ) {
-	require( 'dayjs/esm/locale/' + newLanguage + '.js' );
+	// Silence the warning until https://github.com/vitejs/vite/issues/14102 is fixed
+	// Until then, we copy these files to /dist during build
+	import( /* @vite-ignore */ '../../node_modules/dayjs/esm/locale/' + newLanguage + '.js' );
 	dayjs.locale( newLanguage );
 	dayjs.updateLocale( newLanguage, {
 		weekStart: firstDayOfWeek,

vite.config.ts

@@ -2,7 +2,6 @@ import path from 'path';
 
 import react from '@vitejs/plugin-react';
 import { defineConfig } from 'vite';
-import commonjs from 'vite-plugin-commonjs';
 import i18nextLoader from 'vite-plugin-i18next-loader';
 
 // https://vitejs.dev/config/
@@ -15,7 +14,6 @@ export default defineConfig( {
 		},
 	},
 	plugins: [
-		commonjs(),
 		i18nextLoader( { paths: [ './src/locales' ], namespaceResolution: 'basename' } ),
 		react(),
 	],
@@ -26,7 +24,6 @@ export default defineConfig( {
 	},
 	worker: {
 		plugins: () => [
-			commonjs(),
 			i18nextLoader( { paths: [ './src/locales' ], namespaceResolution: 'basename' } ),
 			react(),
 		],