[VOTE] Release Apache Burr 0.42.0-incubating (RC3)

Hi all,

This is a call for a vote on releasing Apache Burr 0.42.0-incubating
release candidate 3.

The Apache Burr (incubating) PPMC voted to release this RC.

PPMC vote thread:
https://lists.apache.org/thread/t1ktvfyzq885qsylr9w97nwpttlf2w4v

PPMC result: passed with 4 binding +1 (Stefan Krawczyk, Jarek Potiuk,
Jernej Frank, Elijah ben Izzy) and 1 non-binding +1 (André Ahlert).
No -1s. Jarek Potiuk cast a binding +1 on the PPMC thread as an IPMC
member.

Notable changes since 0.41.0:
- Bedrock integration: BedrockAction and BedrockStreamingAction (#677)
- Remove phone-home telemetry per ASF policy
- Add override_state_values support to initialize_from
- Add comparison and identity operators to when() conditions
- Add AST-based linter for undeclared state reads in function actions (#656)
- Add flexible_api decorator to fix mypy override errors (#683)
- Support async with on async persister factory methods (#681)
- Graceful stream shutdown on exceptions in streaming actions (#680)
- Enable Burr UI to be added to existing FastAPI app (#671)
- Add toggle to show/hide input nodes in graph view
- Implement counter app demo in Burr UI (#675)
- Add Next.js landing page for burr.apache.org (#679)
- Add ecosystem page (#661)
- Cloud native AWS deployment support (#666)
- Fix pydantic warnings and minimum pins to pydantic >=2.0 (#668)
- Release-validation CI: builds artifacts, runs Apache RAT, and
  end-to-end smoke tests the wheel from a fresh venv on every PR
- Licensing cleanup: correct MIT attribution for third-party files,
  proper basename-based RAT excludes

The artifacts for this release candidate can be found at:
https://dist.apache.org/repos/dist/dev/incubator/burr/0.42.0-incubating-RC3

The Git tag to be voted upon is: v0.42.0-incubating-RC3
RC tag commit (version bump): 7c64f50619a47332badbe152d2ca1992fd422026
Functional release commit (parent of the version bump):
b707b1d8 -- this is what voters can diff against main to see the
release contents.

Signing key fingerprint:
BB8B72B34AB9A664A109AA17A76CF4C80E4E5355

KEYS file:
https://downloads.apache.org/incubator/burr/KEYS

The artifacts include:
- Full source archive (git archive)
- Wheel (binary distribution with UI and bundled examples)
- Sdist (source for building wheel)

Verification instructions:
https://github.com/apache/burr/blob/main/scripts/README.md

Quick test:
  svn export https://dist.apache.org/repos/dist/dev/incubator/burr/0.42.0-incubating-RC3/
burr-rc3
  cd burr-rc3
  pip install "apache_burr-0.42.0-py3-none-any.whl[learn]"
  burr

Non-blocking observations from PPMC review (filed as follow-ups,
not blockers for this release):
- sdist PKG-INFO License-File metadata doesn't enumerate the bundled
  Magic UI / shadcn MIT components (they ARE present in LICENSE-wheel).
  Tracked: https://github.com/apache/burr/issues/755
- The bundled UI build (~1.7 MB) inside the wheel includes third-party
  JS deps; per-dep enumeration is in the webpack-generated
  main.<hash>.js.LICENSE.txt rather than the wheel's LICENSE.
  Tracked: https://github.com/apache/burr/issues/756
- (Resolved during PPMC review) A stray v0.42.0 git tag from February
  pointed at a long-dead release-prep commit. Already deleted from
  the repo so the final release tag can be cleanly cut.

The vote will run for a minimum of 72 hours.

[ ] +1 Release this package as Apache Burr 0.42.0-incubating
[ ] +0 No opinion
[ ] -1 Do not release this package because...

Thanks,
Elijah
on behalf of the Apache Burr (incubating) PPMC