update & fix CI action

- updated version to 1.26.x
- setup-go@v6 has automated caching enabled by default, but needs the go.mod in order to do so, therefore switched checkout and go setup steps.
[link to setup-go docs](https://github.com/actions/setup-go?tab=readme-ov-file#caching-dependency-files-and-build-outputs)

Author: Niklas Burchhardt

.github/workflows/main.yml

@@ -1,4 +1,3 @@
----
 # based on https://github.com/mvdan/github-actions-golang
 name: CI
 
@@ -18,36 +17,19 @@ jobs:
   test:
     strategy:
       matrix:
-        go-version: [1.25.x]
+        go-version: ["1.26.x"]
         os: [ubuntu-latest]
     runs-on: ${{ matrix.os }}
 
     steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
       - name: Install Go
         uses: actions/setup-go@v6
         with:
           go-version: ${{ matrix.go-version }}
 
-      - name: Checkout code
-        uses: actions/checkout@v6
-
-      # cache go modules
-      - uses: actions/cache@v5
-        with:
-          # In order:
-          # * Module download cache
-          # * Build cache (Linux)
-          # * Build cache (Mac)
-          # * Build cache (Windows)
-          path: |
-            ~/go/pkg/mod
-            ~/.cache/go-build
-            ~/Library/Caches/go-build
-            %LocalAppData%\go-build
-          key: ${{ runner.os }}-go-${{ hashFiles('**/go.sum') }}
-          restore-keys: |
-            ${{ runner.os }}-go-
-
       - name: Downloads the dependencies
         run: make download
 
@@ -64,4 +46,4 @@ jobs:
           config: .github/ct.yaml
 
       - name: Runs helm docs
-        run: make helm-docs
+        run: make helm-docs