ci: remove 3.8 handling

Author: hynek

.github/workflows/ci.yml

@@ -66,7 +66,7 @@ jobs:
         run: |
           DO_MYPY=1
 
-          if [[ "$V" == "3.8" || "$V" == "3.9" || "$V" == "3.14" ]]; then
+          if [[ "$V" == "3.9" || "$V" == "3.14" ]]; then
             DO_MYPY=0
           fi