ci: keep pnpm/action-setup on v4 due to upstream regression

pnpm/action-setup v6 ships a pnpm 11 bootstrap that does not honor the
requested 'version' input, leaving pnpm 11 on PATH after the action
finishes. With this repo's engines.pnpm: 10.33.0 constraint, that
breaks every 'pnpm install' step with ERR_PNPM_UNSUPPORTED_ENGINE.

Tracking upstream:
- pnpm/action-setup#225
- pnpm/action-setup#231

Revert all workflows to v4 and tell Dependabot to ignore v5+ until
upstream stabilizes.

Co-authored-by: Codesmith <codesmith-bot@users.noreply.github.com>

Author: taha-au

.github/dependabot.yaml

@@ -7,6 +7,15 @@ updates:
     commit-message:
       prefix: chore
     labels: []
+    ignore:
+      # pnpm/action-setup v5 and v6 ship a pnpm 11 bootstrap that fails to
+      # honor the requested `version:` input and collides with this repo's
+      # `engines.pnpm: 10.33.0` constraint, breaking `pnpm install` with
+      # ERR_PNPM_UNSUPPORTED_ENGINE.
+      # See https://github.com/pnpm/action-setup/issues/225 and #231.
+      # Stay on v4 until upstream fixes are released.
+      - dependency-name: pnpm/action-setup
+        versions: [">=5"]
 
   - package-ecosystem: npm
     directory: /

.github/workflows/build.yml

@@ -10,7 +10,7 @@ jobs:
         with:
           node-version: "20"
 
-      - uses: pnpm/action-setup@v6
+      - uses: pnpm/action-setup@v4
         with:
           version: 10.33.0
 

.github/workflows/lint.yml

@@ -16,7 +16,7 @@ jobs:
         with:
           node-version: "20"
 
-      - uses: pnpm/action-setup@v6
+      - uses: pnpm/action-setup@v4
         with:
           version: 10.33.0
 

.github/workflows/release.yml

@@ -51,7 +51,7 @@ jobs:
           node-version: "20"
 
       - name: Setup pnpm
-        uses: pnpm/action-setup@v6
+        uses: pnpm/action-setup@v4
         with:
           version: 10.33.0
 

.github/workflows/test-action.yml

@@ -15,7 +15,7 @@ jobs:
         uses: actions/checkout@v6
 
       - name: Setup pnpm
-        uses: pnpm/action-setup@v6
+        uses: pnpm/action-setup@v4
         with:
           version: 10.33.0
 
@@ -69,7 +69,7 @@ jobs:
         uses: actions/checkout@v6
 
       - name: Setup pnpm
-        uses: pnpm/action-setup@v6
+        uses: pnpm/action-setup@v4
         with:
           version: 10.33.0
 

.github/workflows/verify-build.yml

@@ -21,7 +21,7 @@ jobs:
           node-version: "20"
 
       - name: Setup pnpm
-        uses: pnpm/action-setup@v6
+        uses: pnpm/action-setup@v4
         with:
           version: 10.33.0