chore(ci): unify Dockerfile apt deps into one script (#25436)

chore(ci): unify Dockerfile apt deps into install-debian-build-deps.sh

Extract the apt list shared by regression/Dockerfile and tests/e2e/Dockerfile
into scripts/environment/install-debian-build-deps.sh. Resolves the unify TODO
left in regression/Dockerfile.

Side effects:
- Adds mold back to the regression builder (dropped inadvertently in #25411
  when the regression image was switched off the timberio/vector-dev base).
  Regression is a release build, so the link step benefits the most.
- Removes a redundant zlib1g from the e2e list (already pulled in by
  zlib1g-dev).
- Adds perl and pkg-config to the e2e list (they were missing).

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>