fix(ci): use bare yarn install for yarn v1 compatibility

yarn v1 doesn't accept --frozen-lockfile=false (it's not a valid flag
format). And since no lockfile is committed (.gitignore excludes *.lock),
the frozen-lockfile check would fail anyway. Match the existing
gh-pages.yml pattern: plain yarn.

Author: Aldiwildan77

.github/workflows/ci.yml

@@ -22,7 +22,7 @@ jobs:
           node-version: '20'
 
       - name: Install dependencies
-        run: yarn install --frozen-lockfile=false
+        run: yarn
 
       - name: Build
         run: yarn build