Fix pnpm installation error on CI

Per <pnpm/action-setup#135>.

Author: caleb531

.github/workflows/build.yml

@@ -25,7 +25,7 @@ jobs:
           submodules: recursive
 
       - name: Install pnpm
-        uses: pnpm/action-setup@v2
+        uses: pnpm/action-setup@v4
         with:
           version: latest
 

.github/workflows/lint.yml

@@ -19,7 +19,7 @@ jobs:
           submodules: recursive
 
       - name: Install pnpm
-        uses: pnpm/action-setup@v2
+        uses: pnpm/action-setup@v4
         with:
           version: latest
 

.github/workflows/publish.yml

@@ -20,7 +20,7 @@ jobs:
           submodules: recursive
 
       - name: Install pnpm
-        uses: pnpm/action-setup@v2
+        uses: pnpm/action-setup@v4
         with:
           version: latest
 

.github/workflows/tests.yml

@@ -25,7 +25,7 @@ jobs:
           submodules: recursive
 
       - name: Install pnpm
-        uses: pnpm/action-setup@v2
+        uses: pnpm/action-setup@v4
         with:
           version: latest