fix(ci): bump Node.js from 20 to 22 for Astro 6 compatibility

Astro 6 requires Node.js >= 22.12.0.

Author: doomspork

.github/workflows/ci.yml

@@ -12,7 +12,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-node@v6
         with:
-          node-version: 20
+          node-version: 22
           cache: npm
       - run: npm ci
       - name: Build site

.github/workflows/deploy.yml

@@ -22,7 +22,7 @@ jobs:
       - uses: actions/configure-pages@v6
       - uses: actions/setup-node@v6
         with:
-          node-version: 20
+          node-version: 22
           cache: npm
       - run: npm ci
       - run: npm run build