Replace webpack with rspack (#35460)

Given that this bundler is almost a drop-in replacement to webpack, it
might be worth switching. So far it seems everything is working, but
more testing is needed, so I'm setting draft.

- Dev build time is reduced from 10s to 5s
- Prod build time is reduced from 16s to 10s
- JS output size is reduced from 21.3MB to 19.8MB
- CSS output size is increased from 778kB to 818kB

package.json

@@ -16,9 +16,11 @@
     "@mcaptcha/vanilla-glue": "0.1.0-alpha-3",
     "@primer/octicons": "19.18.0",
     "@resvg/resvg-wasm": "2.6.2",
+    "@rspack/cli": "1.5.3",
+    "@rspack/core": "1.5.3",
     "@silverwind/vue3-calendar-heatmap": "2.0.6",
     "@techknowlogick/license-checker-webpack-plugin": "0.3.0",
-    "add-asset-webpack-plugin": "3.0.0",
+    "add-asset-webpack-plugin": "3.1.0",
     "ansi_up": "6.0.6",
     "asciinema-player": "3.10.0",
     "chart.js": "4.5.0",
@@ -30,13 +32,11 @@
     "dayjs": "1.11.18",
     "dropzone": "6.0.0-beta.2",
     "easymde": "2.20.0",
-    "esbuild-loader": "4.3.0",
     "htmx.org": "2.0.7",
     "idiomorph": "0.7.3",
     "jquery": "3.7.1",
     "katex": "0.16.22",
     "mermaid": "11.11.0",
-    "mini-css-extract-plugin": "2.9.4",
     "minimatch": "10.0.3",
     "monaco-editor": "0.53.0",
     "monaco-editor-webpack-plugin": "7.1.0",
@@ -61,8 +61,6 @@
     "vue-bar-graph": "2.2.0",
     "vue-chartjs": "5.3.2",
     "vue-loader": "17.4.2",
-    "webpack": "5.101.3",
-    "webpack-cli": "6.0.1",
     "wrap-ansi": "9.0.2"
   },
   "devDependencies": {