Bump dependencies to bitcoin 0.27 and bech32 0.8

[TheBlueMatt]

Plus various small no_std bits, working towards no_std.

[codecov]

Codecov Report

Merging #1012 (0671ca6) into main (e26c9b0) will increase coverage by 0.04%.
The diff coverage is 75.00%.

@@            Coverage Diff             @@
##             main    #1012      +/-   ##
==========================================
+ Coverage   90.82%   90.86%   +0.04%     
==========================================
  Files          60       60              
  Lines       31455    31584     +129     
==========================================
+ Hits        28568    28698     +130     
+ Misses       2887     2886       -1     

Impacted Files	Coverage Δ
lightning/src/ln/channelmanager.rs	85.89% <ø> (+0.32%)	⬆️
lightning-invoice/src/de.rs	80.73% <66.66%> (-0.34%)	⬇️
lightning-invoice/src/ser.rs	92.19% <100.00%> (ø)
lightning/src/chain/keysinterface.rs	95.36% <0.00%> (-0.05%)	⬇️
lightning/src/ln/functional_tests.rs	97.36% <0.00%> (-0.02%)	⬇️
lightning/src/ln/functional_test_utils.rs	95.74% <0.00%> (+0.82%)	⬆️

---

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[jkczyz]

Is this still [DO NOT MERGE]?

[TheBlueMatt]

Yea, depends on technocreatives/core2#7. I guess we could just bump the CI MSRV version for no-std, but I don't see a reason to - gotta replace the std::io uses we have with core2 anyway before we can ship no-std, so its not like we're in a rush.

[TheBlueMatt]

Dropped the core2 patch since it seems like that isn't happening soon and just set the MSRV for no-std to stable instead for now. I think we can land this.

[devrandom]

ACK

[devrandom]

Interesting test failure though

[TheBlueMatt]

Interesting test failure though

The test failure is unrelated. rustc is (probably) going to make an incompatible libstd change soon, so we're failing on beta. I've argued a bit with them, but there's not really a great other way to accomplish what they want (more ErrorKind variants).

[TheBlueMatt]

This hasn't materially changed since @jkczyz's last review, just merging.