ci: get golang version from modfile (#31)

Reviewed-on: #31
Co-authored-by: t.behrendt <t.behrendt@t00n.de>
Co-committed-by: t.behrendt <t.behrendt@t00n.de>

.gitea/workflows/weekly.yaml

@@ -16,7 +16,7 @@ jobs:
       - name: Setup Go
         uses: actions/setup-go@4a3601121dd01d1626a1e23e37211e3254c1c06c # v6
         with:
-          go-version: "1.26.3"
+          go-version-file: 'go.mod'
       - name: Install yq
         run: |
           sudo wget https://github.com/mikefarah/yq/releases/latest/download/yq_linux_amd64 -O /usr/bin/yq
@@ -29,7 +29,7 @@ jobs:
         id: version_check
         run: |
           NEW_VERSION=$(yq -r '.info.version' openapi.yaml)
-           if [ -f openapi_spec.yaml ]; then
+          if [ -f openapi_spec.yaml ]; then
             OLD_VERSION=$(yq -r '.info.version' openapi_spec.yaml)
           else
             OLD_VERSION="0.0.0"