ci: fix npm install peer dependency conflict

Updated .github/workflows/build.yml to use `npm install --legacy-peer-deps` in all installation steps.
This resolves the `ERESOLVE` error caused by conflicting peer dependencies between `anchor-bankrun` and `@coral-xyz/anchor`.

Co-authored-by: ethan-hurst <23321960+ethan-hurst@users.noreply.github.com>

Author: google-labs-jules[bot]

.github/workflows/build.yml

@@ -30,10 +30,10 @@ jobs:
 
       - name: Install Dependencies
         run: |
-          npm install
-          cd programs/helix-staking && npm install
-          cd ../../app/web && npm install
-          cd ../../services/indexer && npm install
+          npm install --legacy-peer-deps
+          cd programs/helix-staking && npm install --legacy-peer-deps
+          cd ../../app/web && npm install --legacy-peer-deps
+          cd ../../services/indexer && npm install --legacy-peer-deps
 
       - name: Run Bankrun Tests (Program)
         run: |