fix(ci): keep original tarball filename for checksum verification

sha256sum --check matches by filename, so the downloaded tarball
must keep its original name to match the checksums.txt entry.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: wyattwalter

.github/workflows/helm-docs.yml

@@ -40,10 +40,11 @@ jobs:
         run: |
           HELM_DOCS_VERSION=1.14.2
           BASE_URL="https://github.com/norwoodj/helm-docs/releases/download/v${HELM_DOCS_VERSION}"
+          TARBALL="helm-docs_${HELM_DOCS_VERSION}_Linux_x86_64.tar.gz"
           curl -sSL "${BASE_URL}/helm-docs_${HELM_DOCS_VERSION}_checksums.txt" -o checksums.txt
-          curl -sSL "${BASE_URL}/helm-docs_${HELM_DOCS_VERSION}_Linux_x86_64.tar.gz" -o helm-docs.tar.gz
+          curl -sSL "${BASE_URL}/${TARBALL}" -o "${TARBALL}"
           sha256sum --check --ignore-missing checksums.txt
-          tar xzf helm-docs.tar.gz helm-docs
+          tar xzf "${TARBALL}" helm-docs
           sudo mv helm-docs /usr/local/bin/
 
       - name: Check values schema