fix(action): hardcode public GitHub URLs for binary download

The sr binary is always hosted on public GitHub. Using GITHUB_API_URL
and GITHUB_SERVER_URL env vars caused 401 errors on GHES runners where
these point to the enterprise instance.

Author: urmzd

action.yml

@@ -108,7 +108,7 @@ runs:
 
         # Resolve action ref to a release tag.
         # exact tag (v3.5.2) → prefix match (v3 → v3.x.x) → latest release
-        API="${GITHUB_API_URL:-https://api.github.com}/repos/${SR_REPO}"
+        API="https://api.github.com/repos/${SR_REPO}"
         TAGS=$(curl -fsSL "${API}/releases?per_page=100" | jq -r '.[].tag_name')
         RELEASE_TAG=$(echo "$TAGS" | grep -xF "$SR_REF" | head -1 || true)
         [ -z "$RELEASE_TAG" ] && RELEASE_TAG=$(echo "$TAGS" | grep "^${SR_REF}\." | head -1 || true)
@@ -120,7 +120,7 @@ runs:
         fi
         echo "Resolved ref=${SR_REF} → release=${RELEASE_TAG}"
 
-        URL="${GITHUB_SERVER_URL:-https://github.com}/${SR_REPO}/releases/download/${RELEASE_TAG}/${BINARY_NAME}"
+        URL="https://github.com/${SR_REPO}/releases/download/${RELEASE_TAG}/${BINARY_NAME}"
         echo "Downloading ${URL}"
         curl -fsSL "$URL" -o "$DEST"