update flatpak boost download link

Author: treellama

flatpak/shared/boost.yml

@@ -6,5 +6,5 @@ build-commands:
 sources:
   - sha256: 475d589d51a7f8b3ba2ba4eda022b170e562ca3b760ee922c146b6c65856ef39
     type: archive
-    url: https://boostorg.jfrog.io/artifactory/main/release/1.79.0/source/boost_1_79_0.tar.bz2
+    url: https://archives.boost.io/release/1.79.0/source/boost_1_79_0.tar.bz2
 cleanup: [/include, /lib/*.a, /lib/debug, /lib/cmake]