--force keygen in action for fresh builds

.github/workflows/anchor.yml

@@ -111,7 +111,8 @@ jobs:
       - name: Display Versions and Install pnpm
         run: |
           solana -V
-          solana-keygen new --no-bip39-passphrase
+          # it's okay to use --force in github action since all programs are tested in isolation
+          solana-keygen new --no-bip39-passphrase --force
           rustc -V
           anchor -V
           npm i -g pnpm