Update test action to use go 1.19

Author: smowton

.github/workflows/go-tests.yml

@@ -11,10 +11,10 @@ jobs:
     name: Test Linux (Ubuntu)
     runs-on: ubuntu-latest
     steps:
-      - name: Set up Go 1.18.1
+      - name: Set up Go 1.19
         uses: actions/setup-go@v3
         with:
-          go-version: 1.18.1
+          go-version: 1.19
         id: go
 
       - name: Check out code