Cut back on number of CI jobs

.github/workflows/test.yml

@@ -9,8 +9,8 @@ jobs:
         swiftver:
           - swift:5.2
           - swift:5.3
-          - swift:5.4
           - swift:5.5
+          - swiftlang/swift:nightly-5.6
           - swiftlang/swift:nightly-main
         swiftos:
           - focal
@@ -39,19 +39,15 @@ jobs:
         dbimage:
           - postgres:14
           - postgres:13
-          - postgres:12
           - postgres:11
-        dbauth:
-          - trust
-          - md5
-          - scram-sha-256
-        swiftver:
-          # Only test latest Swift for integration tests, issues from older Swift versions that don't show
-          # up in the unit tests are fairly unlikely.
-          - swift:5.5
-        swiftos:
-          - focal
-    container: ${{ format('{0}-{1}', matrix.swiftver, matrix.swiftos) }}
+        include:
+          - dbimage: postgres:14
+            dbauth: scram-sha-256
+          - dbimage: postgres:13
+            dbauth: md5
+          - dbimage: postgres:11
+            dbauth: trust
+    container: swift:5.5-focal
     runs-on: ubuntu-latest
     env:
       LOG_LEVEL: debug
@@ -119,7 +115,7 @@ jobs:
           - scram-sha-256
         xcode:
           - latest-stable
-          - latest
+          #- latest
     runs-on: macos-11
     env:
       LOG_LEVEL: debug