Add consolidated 7.0.0 changelog entry

[Copilot]

• Read all 7.0.0-dev and 7.0.0-rc changelog entries
• Create consolidated 7.0.0 changelog entry with highlights note
• Update python/pyproject.toml version to match
• Cross-check every bullet from dev/rc sections — added 3 missing items:
  • default_respond_on_commit_func removal from public API (rc1)
  • Python test dependency update Update wheel pin to >0.46.2 #7609 (dev8)
  • Want-Repr-Digest support for /node/snapshot/{snapshot_name} (dev10)
• Validate with extract-release-notes.py

[achamayou]

@copilot make sure you didn't miss anything from the existing 7.0.0-dev and 7.0.0-rc sections!

[achamayou]

Closes #7816

[Copilot]

@copilot make sure you didn't miss anything from the existing 7.0.0-dev and 7.0.0-rc sections!

I did a line-by-line cross-check of every bullet in every dev/rc section and found 3 items I had missed:

1. ccf::endpoints::default_respond_on_commit_func removed from public API (from rc1)
2. Python test dependency update Update wheel pin to >0.46.2 #7609 (from dev8)
3. Want-Repr-Digest/Repr-Digest support for /node/snapshot/{snapshot_name} — was only mentioned for ledger_chunk endpoints but the original dev10 entry also covers snapshot endpoints

All three are now included in commit 6f2f834.

[eddyashton]

This seems surprisingly small. Is this the only dependency diff between 6.latest and 7.0.0? I know we've backported some, but wondering if this is just an accident from what ended up in the CHANGELOG.

[achamayou]

It is according to our entries, but it's clearly not the whole stories because we now depend on the rust toolchain and several rust crates.