The Git team has tagged Git v2.49.0.gl2, which backports two important
performance optimizations:

  - An improvement for git-bundle(1) that optimizes performance when
    creating Git bundles. The algorithm used to figure out whether there
    are duplicate references had quadratic complexity, which had the
    result that git-bundle(1) may run for days in repositories with a
    huge number of refs.

  - An improvement for git-cat-file(1) that allows filtering objects by
    object type. This mode knows to make use of packfile bitmaps to
    locate these objects. This significantly speeds up `--batch` modes
    where we scan through all objects of a specific type, which
    previously required us to read through all packfiles.

The new filtering mode for git-cat-file(1) will require further changes
to RPCs to pass those new options. This will be done in subsequent merge
requests.