Revert "removing macos-latest from linueup ... something changed betw…

…een now and 10:30 to the mac that has caused the macos tests to fail"

This reverts commit 5f6c313.

At this point, it seems that the server had actually crashed ... new server location teething pains ..

.github/workflows/ci.yml

@@ -13,7 +13,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ ubuntu-20.04 ]
+        os: [ ubuntu-20.04, macos-latest ]
         smalltalk: [ GemStone64-3.7.0, GemStone64-3.6.6, GemStone64-3.5.8 ]
         config: [ .smalltalkA.ston, .smalltalkB.ston ]
     runs-on: ${{ matrix.os }}