chore: bump MSRV to 1.85.0

[ValuedMammal]

Bump bdk_wallet MSRV to 1.85.0.

Restructure repository to be a single rust project.

Small cleanups to .github/workflows by moving away from unmaintained actions-rs/toolchain in favor of dtolnay/rust-toolchain.

Follow-ups

• Address zizmor code scanning results
• Use rust edition 2024. May have to remove some "unnecessary binding modifiers"
• Consider updating .github/CODEOWNERS

fix #289

Notes to the reviewers

Changelog notice

Changed

- Raise project MSRV to 1.85.0
- ci: Migrate to `dtolnay/rust-toolchain`
- ci: Add zizmor.yml config

Checklists

All Submissions:

• I've signed all my commits
• I followed the contribution guidelines

[coveralls]

Pull Request Test Coverage Report for Build 18041569734

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.4%) to 85.211%

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Totals
Change from base Build 17957725258:	0.4%
Covered Lines:	3895
Relevant Lines:	4571

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💛 - Coveralls

[thunderbiscuit]

Concept ACK. See comment on workspace. Good move away from the deprecated action-rs/rust-toolchain action.

[thunderbiscuit]

I'm personally not a fan of the "pin the hash on the actions" that zizmor recommends here.

If you want to address the zizmor warning you're getting here, you could do what we do for bdk-ffi. You add a file called zizmor.yml at the root of the .github/ directory with the following:

# This is a configuration file for the zizmor action defined in .github/workflows/zizmor.yaml

rules:
  # Disable the rule requiring all actions be pinned to a specific hash
  unpinned-uses:
    config:
      policies:
        "*": any

[thunderbiscuit]

Tested ACK 6260274.

I'm getting one little clippy warning locally:

error: the following explicit lifetimes could be elided: 'a
    --> src/wallet/mod.rs:1192:25
     |
1192 |     pub fn transactions<'a>(&'a self) -> impl Iterator<Item = WalletTx<'a>> + 'a {
     |                         ^^   ^^                                        ^^     ^^
     |
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
     = note: `-D clippy::needless-lifetimes` implied by `-D warnings`
     = help: to override `-D warnings` add `#[allow(clippy::needless_lifetimes)]`
help: elide the lifetimes
     |
1192 -     pub fn transactions<'a>(&'a self) -> impl Iterator<Item = WalletTx<'a>> + 'a {
1192 +     pub fn transactions(&self) -> impl Iterator<Item = WalletTx<'_>> + '_ {

But this is related to my default toolchain being 1.85. The warning disappears if I build using 1.89. See #315 for my recommendation on how to fix that sort of issue. Not required for this PR, just pointing it out.

[thunderbiscuit]

Also note that I think the rust-version file was there to help the actions-rs/toolchain action (that's a file it uses to decide on rust compiler version). Since you've moved away from this action it might be possible to remove the file entirely (or at least we should know why we need to keep it if another tool/workflow/dev is using it).

[ValuedMammal]

In 2a5c492 I added an exception to the unpinned-uses rule specifically for dtolnay/rust-toolchain. One slight problem is that the upstream repo only has one v1 tag that seems to be continually overwritten (i.e. insecure from a code scanning perspective). We could pin it to a hash but that would require more hands-on involvement if we ever want to update it. If there's alternatives to dtolnay for installing a rust toolchain we could explore that too.

[thunderbiscuit]

ACK eceb1a3. Nice cleanup.

[ValuedMammal]

📌 Accidentally clobbered when I merged the two READMEs together. Same on line 4.