chore: prepare Tokio v1.30.0 release

[bcardarella]

As requested by @Darksonn in #5887

First time doing this for this project so please let me know if if I need to correct something. I went through all of the commits after the v1.29.1 release on June 29 and tried to sort them into the CHANGELOG buckets that made sense but may have misplaced some.

1.30.0 (August 9, 2023)

This release bumps the MSRV of Tokio to 1.63. (#5887)

Changed

• tokio: reduce LLVM code generation (#5859)
• io: support --cfg mio_unsupported_force_poll_poll flag (#5881)
• sync: make const_new methods always available (#5885)
• sync: avoid false sharing in mpsc channel (#5829)
• rt: pop at least one task from inject queue (#5908)

Added

• sync: add broadcast::Sender::new (#5824)
• net: implement UCred for espidf (#5868)
• fs: add File::options() (#5869)
• time: implement extra reset variants for Interval (#5878)
• process: add {ChildStd*}::into_owned_{fd, handle} (#5899)

Removed

• tokio: removed unused tokio_* cfgs (#5890)
• remove build script to speed up compilation (#5887)

Documented

• sync: mention lagging in docs for broadcast::send (#5820)
• runtime: expand on sharing runtime docs (#5858)
• io: use vec in example for AsyncReadExt::read_exact (#5863)
• time: mark Sleep as !Unpin in docs (#5916)
• process: fix raw_arg not showing up in docs (#5865)

Unstable

• rt: add runtime ID (#5864)
• rt: initial implementation of new threaded runtime (#5823)

[bcardarella]

Updated to resolve @NobodyXu's change requests

[taiki-e]

Thanks!

Several changes in the changelog seem to be unrelated to tokio crate. (FYI, the directory-level commit history shows only changes related to tokio crate: https://github.com/tokio-rs/tokio/commits/master/tokio)

[bcardarella]

@taiki-e made your requested changes

[Darksonn]

Thank you for taking the time to prepare this PR!

[Darksonn]

Please turn all of the changelog lines into links. Here's an example of how it should look with two of the links:

Suggested change

	- rt: add runtime ID (#5864)
	- rt: initial implementation of new threaded runtime (#5823)
	- rt: add runtime ID ([#5864])
	- rt: initial implementation of new threaded runtime ([#5823])
	[#5823]: https://github.com/tokio-rs/tokio/pull/5823
	[#5864]: https://github.com/tokio-rs/tokio/pull/5864

Note the two changes:

• Square brackets added around PR number in the commit message.
• Links added at the bottom, in sorted order.

[bcardarella]

@Darksonn done!

[bcardarella]

@taiki-e done!

[bcardarella]

@taiki-e thank you! Sorry it took a few passes to get it where you all wanted, thanks for holding my hand 🎉

[bcardarella]

What are the next steps? Do I have to do anything else?

[Darksonn]

Once the changelog is ready, you just need to wait for me to get to a laptop. I will merge it at the same time as when I publish it.

[Darksonn]

This link appears twice. Please double check the links. We usually sort them to make them easier to see.

[bcardarella]

@Darksonn done, I did originally consider sorting but I looked at a few prior entries and they weren't sorted but I agree it is best

[Darksonn]

I guess it depends on who wrote it. I always sort them.

[bcardarella]

I'm not sure why CI keeps failing, is that something I need to address?

[Darksonn]

No. I opened an issue #5920 and I will restart ci.

[bcardarella]

@Darksonn sounds good, if any other changes are necessary for this PR I'll be here ready to fix!

[Darksonn]

I'm happy with this. I'll merge it later when I get to a laptop.

Please double check whether any new things have been merged in the meantime.

[bcardarella]

will do!

[bcardarella]

@Darksonn there are two commits that have happened since I opened this PR. They are:

• ci: fix MIRI tests ci: fix MIRI tests #5919
• process: add {ChildStd*}::into_owned_{fd, handle} process: Impl {ChildStd*}::into_owned_{fd, handle} #5899

I asume the ci one shouldn't be included as indicated from prior comments. Is #5899 OK to include?

[bcardarella]

@Darksonn nm, looks like you took care of it

[Darksonn]

Yeah, thanks for taking the time to prepare this PR. It will be published shortly.