Install git-annex via datalad/packages so not to install outdated version now

Author: yarikoptic

.appveyor.yml

@@ -62,7 +62,7 @@ environment:
   APPVEYOR_BUILD_WORKER_IMAGE: Ubuntu2204
   INSTALL_SYSPKGS: python3-venv xz-utils jq libffi7
   # system git-annex is way too old, use better one
-  INSTALL_GITANNEX: git-annex -m deb-url --url http://snapshot.debian.org/archive/debian/20210906T204127Z/pool/main/g/git-annex/git-annex_8.20210903-1_amd64.deb
+  INSTALL_GITANNEX: git-annex -m datalad/packages
   CODECOV_BINARY: https://uploader.codecov.io/latest/linux/codecov
 
   matrix: