[antlir2][snapshot] remove offline from RepoInfo provider

Summary:
This is never used. The subtarget is still useful for local testing, but it
doesn't need to be on the provider

Test Plan: testhard

Reviewed By: justintrudell

Differential Revision: D67980782

fbshipit-source-id: 536e16f7bdf8ed08557b4846fbca83e1c9da29de

antlir/antlir2/package_managers/dnf/rules/repo.bzl

@@ -14,7 +14,6 @@ RepoInfo = provider(fields = [
     "dnf_conf_json",  # JSON serialized dnf.conf KV for this repo
     "gpg_keys",  # Optional artifact against which signatures will be checked
     "id",  # Repo name
-    "offline",  # Complete offline archive of repodata and all RPMs
     "repodata",  # Populated repodata/ directory
 ])
 
@@ -89,7 +88,6 @@ def _impl(ctx: AnalysisContext) -> list[Provider]:
             logical_id = ctx.attrs.logical_id,
             repodata = repodata,
             gpg_keys = ctx.attrs.gpg_keys,
-            offline = offline,
             base_url = ctx.attrs.base_url,
             all_rpms = rpm_infos,
             dnf_conf_json = dnf_conf_json,