Allow uploading commit-map file

Git filter-repo produces a commit-map file that does not have a file
extension. This prevents it from being uploaded without renaming the
file. Removes file type validation to permit upload.

app/views/projects/cleanup/_show.html.haml

@@ -22,7 +22,7 @@
             = _("Choose a file")
           %span.prepend-left-default.js-filename
             = _("No file selected")
-          = f.file_field :bfg_object_map, accept: 'text/plain', class: "hidden js-object-map-input", required: true
+          = f.file_field :bfg_object_map, class: "hidden js-object-map-input", required: true
         .form-text.text-muted
           = _("The maximum file size allowed is %{size}.") % { size: number_to_human_size(Gitlab::CurrentSettings.max_attachment_size.megabytes) }
       = f.submit _('Start cleanup'), class: 'btn btn-success'

changelogs/unreleased/reduce-repo-size.yml

+---
+title: Add support for `git filter-repo` to repository cleanup
+merge_request: 33576
+author:
+type: added