chore: remove 1.15 support

Author: Reasno

.github/workflows/go.yml

@@ -9,7 +9,7 @@ jobs:
   build:
     strategy:
       matrix:
-        go-version: [1.15.x,1.16.x,1.17.x]
+        go-version: [1.16.x,1.17.x]
     runs-on: ubuntu-latest
     services:
       redis: