chore: Use pnpm install --frozen-lockfile in GHA (#57)

Author: aster-mnch

.github/workflows/autofix.yml

@@ -25,7 +25,7 @@ jobs:
           node-version: lts/*
 
       - name: Install
-        run: pnpm install
+        run: pnpm install --frozen-lockfile
 
       - name: Lint
         run: pnpm run lint --fix

.github/workflows/ci.yml

@@ -20,7 +20,7 @@ jobs:
           node-version: lts/*
 
       - name: Install
-        run: pnpm install
+        run: pnpm install --frozen-lockfile
 
       - name: Typecheck
         run: pnpm run typecheck