Release v4.0.0-rc

[ascjones]

The first release candidate is here! This is the first release which could become the final
v4.0.0. Any subsequent release candidates should only contain bug fixes: no API changes,
breaking or otherwise.

Breaking Changes

1. We've renamed some of the generated message methods on the ContractRef struct. They
   have been changed from _checked to try_ (#1621)
2. We have removed the Default implementation for AccountIds. This is because of
   security concerns around the use of the zero address which has a known private key in
   the sr25519 and ed25519 curves (#1255).

Added

• E2E: expose call dry-run method ‒ #1624

Changed

• Remove Default implementation for AccountId ‒ #1255
• Rename _checked codegen call methods with try_ ‒ #1621
• Bump Substrate and subxt dependencies ‒ #1549

[ascjones]

Waiting for #1255 and a cargo-contract release PR (since ink_e2e depends on contract-build)

[ascjones]

use-ink/cargo-contract#937 (review)

[codecov-commenter]

Codecov Report

Merging #1637 (9ce2bd6) into master (ce64dbe) will increase coverage by 0.01%.
The diff coverage is n/a.

❗ Current head 9ce2bd6 differs from pull request most recent head 26d82a2. Consider uploading reports for the commit 26d82a2 to get more accurate results

@@            Coverage Diff             @@
##           master    #1637      +/-   ##
==========================================
+ Coverage   64.78%   64.80%   +0.01%     
==========================================
  Files         207      207              
  Lines        6376     6376              
==========================================
+ Hits         4131     4132       +1     
+ Misses       2245     2244       -1     

Impacted Files	Coverage Δ
crates/allocator/src/bump.rs	88.23% <0.00%> (-0.85%)	⬇️
crates/ink/ir/src/ir/attrs.rs	78.26% <0.00%> (+0.28%)	⬆️
crates/ink/ir/src/ast/attr_args.rs	84.78% <0.00%> (+2.17%)	⬆️

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