ci(gpu): point pr-downloader at BAR content CDN

Map downloads for newer BAR maps (Shallow Straits, Death Valley, Seths
Ravine Remake, Houses of Tripolis) failed with errorID 2 because the
launcher left pr-downloader on its legacy springrts.com defaults, which
only mirror older maps. Export PRD_RAPID_REPO_MASTER and
PRD_HTTP_SEARCH_URL so rapid and the HTTP map search resolve against
BAR's own content network, where these maps are hosted.

Author: Mearman

.github/workflows/macos-build-gpu.yml

@@ -302,6 +302,13 @@ jobs:
           # DYLD_FALLBACK is safe (does not shadow system OpenGL); Zink finds
           # the bundled Vulkan loader through it.
           export DYLD_FALLBACK_LIBRARY_PATH="\$RES/lib"
+          # pr-downloader defaults to the legacy springrts.com servers, which
+          # only mirror older maps. Newer BAR maps (e.g. Shallow Straits,
+          # Death Valley) live solely on BAR's CDN, so without these overrides
+          # the map search returns zero results ("Download Failed ... errorID
+          # 2"). Point rapid and the HTTP map search at BAR's content network.
+          export PRD_RAPID_REPO_MASTER="https://repos-cdn.beyondallreason.dev/repos.gz"
+          export PRD_HTTP_SEARCH_URL="https://files-cdn.beyondallreason.dev/find"
           cd "\$USER_DATA"
           exec "\$RES/bin/spring" --isolation-dir "\$USER_DATA" --menu "BYAR Chobby $LOBBY_VERSION" "\$@"
           LAUNCHER