Added Stan r-universe and cmdstanr as a dependency so some tests aren't skipped.

Author: VisruthSK

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

@@ -40,10 +40,11 @@ jobs:
           r-version: ${{ matrix.config.r }}
           http-user-agent: ${{ matrix.config.http-user-agent }}
           use-public-rspm: true
+          extra-repositories: 'https://stan-dev.r-universe.dev'
 
       - uses: r-lib/actions/setup-r-dependencies@v2
         with:
-          extra-packages: any::rcmdcheck, any::BH, any::RcppEigen, any::vdiffr
+          extra-packages: any::rcmdcheck, any::BH, any::RcppEigen, any::vdiffr, any::cmdstanr
           needs: check
 
       - uses: r-lib/actions/check-r-package@v2

.github/workflows/test-coverage.yaml

@@ -21,10 +21,11 @@ jobs:
       - uses: r-lib/actions/setup-r@v2
         with:
           use-public-rspm: true
+          extra-repositories: 'https://stan-dev.r-universe.dev'
 
       - uses: r-lib/actions/setup-r-dependencies@v2
         with:
-          extra-packages: any::covr, any::xml2, any::vdiffr
+          extra-packages: any::covr, any::xml2, any::vdiffr, any::cmdstanr
           needs: coverage
 
       - name: Test coverage