Repository size increases after fetch for repositories with multi-pack index (MIDX) files

We've identified an issue where the size of a repository increases significantly after a git fetch operation, particularly for forked repositories using multi-pack index (MIDX) files. This problem appears to be introduced by commit 7f514b7a (midx: read RIDX chunk when present, 2022-01-25).

• The issue seems to be related to the reading of RIDX chunks from MIDX files.
• Disabling the reading of RIDX chunks using GIT_TEST_MIDX_READ_RIDX=0 resolves the issue.

More context and steps to reproduce can be found here: gitlab#515314 (comment 2357686139)