Update build.yml to add a rnglib test build.

Add a test for --enable-rnglibs

Author: Don-Ward

.github/workflows/build.yml

@@ -192,6 +192,7 @@ jobs:
         -  { os: ubuntu-latest, name: 'No Concurrency', opt: '--disable-concurrency' }
         -  { os: ubuntu-latest, name: 'Heap Test',      opt: '--enable-debugheap  --enable-verifyheap' }
         -  { os: ubuntu-latest, name: 'Thin Build',     opt: '--enable-thin' }
+        -  { os: ubuntu-latest, name: 'Rng Libraries',  opt: '--enable-rnglibs' }
     steps:
     - name: Checkout
       uses: actions/checkout@v3