fix sdk parsing

Author: PolynomialDivision

.github/workflows/build.yml

@@ -38,11 +38,15 @@ jobs:
       - name: Determine latest OpenWrt SDK version
         id: sdk_version
         run: |
-          # Use wget or curl to scrape the OpenWrt download server and extract the latest SDK tar file URL
+          # Use curl to scrape the OpenWrt download server and extract the latest SDK tar file URL
           SDK_URL=$(curl -s https://downloads.openwrt.org/snapshots/targets/ath79/generic/ | \
-                    grep -oP 'href="\K[^"]*-gcc-[^"]+_musl.Linux-x86_64.tar.zst' | \
-                    sort -V | tail -n 1)
+                    grep -oP 'href="openwrt-sdk-[^"]+\.tar\.zst"' | \
+                    sort -V | tail -n 1 | \
+                    sed 's/href="//' | sed 's/"//')
+
           echo "Latest OpenWrt SDK URL: https://downloads.openwrt.org/snapshots/targets/ath79/generic/$SDK_URL"
+
+          # Save the SDK URL into an environment variable so it can be used in the next steps
           echo "sdk_url=https://downloads.openwrt.org/snapshots/targets/ath79/generic/$SDK_URL" >> $GITHUB_ENV
 
       # Step 5: Download OpenWrt SDK if not cached