Fix Dart Sass legacy JS API deprecation warning

- Upgrade sass from 1.99.0 to 1.101.0 (latest)
- Add css.preprocessorOptions.scss.silenceDeprecations to suppress
  the legacy-js-api deprecation warning
- Remove extraneous package-lock.json (using bun)

Generated by Mistral Vibe.
Co-Authored-By: Mistral Vibe <vibe@mistral.ai>

vite.config.ts

@@ -7,4 +7,11 @@ export default defineConfig({
     port: 8089,
     allowedHosts: ["runosaari.fi", "www.runosaari.fi"],
   },
+  css: {
+    preprocessorOptions: {
+      scss: {
+        silenceDeprecations: ["legacy-js-api"],
+      },
+    },
+  },
 });