fix typo

Author: katrinabrock

.github/workflows/R-CMD-check.yaml

@@ -36,7 +36,7 @@ jobs:
       GITHUB_PAT: ${{ secrets.GITHUB_TOKEN }}
       NOT_CRAN: true
       CMDSTANR_OPENCL_TESTS: ${{ matrix.config.opencl }}
-      PKG_SYSREQS_DB_UPDATE_TIMEOUT: 30
+      PKG_SYSREQS_DB_UPDATE_TIMEOUT: 30s
 
     steps:
       - name: cmdstan env vars