Simplify CI: just test on Go 1.15

Author: oliveagle

.github/workflows/ci.yml

@@ -2,70 +2,18 @@ name: CI
 
 on:
   push:
-    branches: [master, main, v*]
+    branches: [master, main]
   pull_request:
     branches: [master, main]
 
 jobs:
   test:
     runs-on: ubuntu-latest
-    strategy:
-      matrix:
-        go-version: ['1.15', '1.20', '1.21', '1.22', '1.23']
-
     steps:
       - uses: actions/checkout@v4
-
       - name: Set up Go
         uses: actions/setup-go@v5
         with:
-          go-version: ${{ matrix.go-version }}
-
-      - name: Cache Go modules
-        uses: actions/cache@v4
-        with:
-          path: |
-            ~/.cache/go-build
-            ~/go/pkg/mod
-          key: ${{ runner.os }}-go-${{ matrix.go-version }}-${{ hashFiles('**/go.sum') }}
-          restore-keys: |
-            ${{ runner.os }}-go-${{ matrix.go-version }}-
-
+          go-version: '1.15'
       - name: Test
-        run: go test -v ./...
-
-      - name: Test with Coverage
-        if: matrix.go-version == '1.22'
-        run: go test -coverprofile=coverage.out ./...
-
-      - name: Upload Coverage
-        if: matrix.go-version == '1.22'
-        uses: codecov/codecov-action@v4
-        with:
-          file: ./coverage.out
-          flags: unittests
-          name: codecov-umbrella
-          fail_ci_if_error: false
-
-  lint:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-
-      - name: Set up Go
-        uses: actions/setup-go@v5
-        with:
-          go-version: '1.22'
-
-      - name: Run go vet
-        run: go vet ./...
-
-      - name: Check formatting
-        run: |
-          # Only check .go files
-          unformatted=$(gofmt -l *.go)
-          if [ -n "$unformatted" ]; then
-            echo "Code needs formatting:"
-            gofmt -d *.go
-            exit 1
-          fi
+        run: go test ./...