#131679 set maintenance.auto=false in the treeless install checkout to stop the
commit-graph lazy-fetch loop (#127711). That also switched off the post-fetch
`gc --auto` that git <= 2.53 runs after every lazy fetch, so packs piled up
between updates and only folded on a manual `hermes update` / `--check`
(nothing runs `--check` automatically).
The loop needs a commit-graph write, and gc.writeCommitGraph=false +
fetch.writeCommitGraph=false already stop gc and fetch from writing one.
maintenance.commit-graph.enabled=false closes the last writer (a commit-graph
maintenance task, e.g. from a user's global maintenance.strategy) while
leaving automatic maintenance, and its gc fold, on.
Checkouts that already got maintenance.auto=false from the first cut are
converged: the next update/--check unsets exactly that value.
Measured on a real tree:0 clone with a Bloom commit-graph, 100 lazy fetches
after one updater run:
git 2.53.0: main 101 packs, this change 1 pack, 0 commit-graph writes
git 2.55.0: 101 / 101 (stock 2.55 maintenance does not fold), 0 writes
35eacd248a