fix(ci): correct Gitea HTTP auth username in codemagic push step

Was using 'sysadmin' (Linux system user) instead of 'SilverLABS' (Gitea account).

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

codemagic.yaml

@@ -65,7 +65,7 @@ workflows:
           mv altstore-source.tmp.json altstore-source.json
 
           # Commit and push updated source
-          git remote set-url origin "https://sysadmin:$GITEA_TOKEN@git.silverlabs.uk/$GITEA_REPO.git"
+          git remote set-url origin "https://SilverLABS:$GITEA_TOKEN@git.silverlabs.uk/$GITEA_REPO.git"
           git config user.name "Codemagic"
           git config user.email "ci@silverlabs.uk"
           git add altstore-source.json