ci(asm): pin pnpm via action-setup to avoid ERR_PNPM_IGNORED_BUILDS

The ASM workflow installed pnpm with 'npm install --global pnpm', which
resolves to the latest pnpm release. Recent pnpm releases escalate
'Ignored build scripts' from a warning to a hard error (ERR_PNPM_IGNORED_BUILDS),
which makes 'pnpm install --frozen-lockfile' fail for any project with
transitive build scripts that aren't on an explicit allow-list. The asm
projects pull in bufferutil + utf-8-validate via @solana/web3.js -> ws.

Switch to pnpm/action-setup@v4 (which the anchor, native, pinocchio, and
typescript workflows already use). That action currently installs pnpm
10.33.0, which still treats this as a warning and lets the install succeed.

Author: mikemaccana-edwardbot

.github/workflows/solana-asm.yml

@@ -103,6 +103,12 @@ jobs:
       failed_projects: ${{ steps.set-failed.outputs.failed_projects }}
     steps:
       - uses: actions/checkout@v4
+      # The previous `npm install --global pnpm` step picked up a pnpm release that
+      # treats ignored build scripts (bufferutil, utf-8-validate) as a hard error and
+      # fails `pnpm install --frozen-lockfile`. The other workflows (anchor, native,
+      # pinocchio, typescript) use pnpm/action-setup@v4, which pins a known-good pnpm
+      # release (10.33.0 at time of writing) that only warns. Match that here.
+      - uses: pnpm/action-setup@v4
       - name: Use Node.js
         uses: actions/setup-node@v4
         with:
@@ -180,8 +186,8 @@ jobs:
           # Make the script executable
           chmod +x build_and_test.sh
 
-          # Install pnpm
-          npm install --global pnpm
+          # pnpm is installed by pnpm/action-setup@v4 above. Avoid `npm install --global pnpm`
+          # here because that resolves to pnpm 10+, which errors on ignored build scripts.
 
           # Install sbpf assembler
           cargo install --git https://github.com/blueshift-gg/sbpf.git