🤖 ci: remove duplicate Go version input in govulncheck step

Use `go-version-input` for `golang/govulncheck-action` instead of
`go-version-file` to avoid setup-go warnings about both version input
modes being set.

---

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Author: ThomasK33

.github/workflows/ci.yaml

@@ -101,7 +101,7 @@ jobs:
       - name: Run govulncheck
         uses: golang/govulncheck-action@b625fbe08f3bccbe446d94fbf87fcc875a4f50ee # v1
         with:
-          go-version-file: go.mod
+          go-version-input: 1.25.7
           go-package: ./...
 
   test: