chore: remove stale qs/picomatch changeset

This changeset was added in #404 but the identical qs/picomatch CVE fix
already shipped to main via #450 (commit 3a1ec21) and is in the published
mrt-utilities CHANGELOG. The qs/picomatch overrides in pnpm-workspace.yaml
and their resolved lockfile versions are identical between main and
develop — there is no actual dependency change in this integration diff.

Left in place, it would produce a spurious @salesforce/mrt-utilities patch
bump duplicating an already-released CHANGELOG entry.

Author: clavery