Update .github/workflows/build.yml

Author: sol

.github/workflows/build.yml

@@ -18,11 +18,8 @@ jobs:
     strategy:
       matrix:
         os:
-          - ubuntu-18.04
+          - ubuntu-20.04
         ghc:
-          - '7.4'
-          - '7.6'
-          - '7.8'
           - '7.10'
           - '8.0'
           - '8.2'
@@ -32,6 +29,9 @@ jobs:
           - '8.10'
           - '9.0'
           - '9.2'
+          - '9.4'
+          - '9.6'
+          - '9.8'
         include:
           - os: macos-latest
             ghc: latest