CI failing MSRV cargo check with new chrono 0.4.25

[jakelishman]

Bug Description

chrono 0.4.25 released yesterday, and it looks like it's causing problems in cargo check on Rust 1.48. I bumped into this on #3185. Looks like chrono's MSRV is 1.56.1 (implied by their CI), so they technically haven't made a breaking change in their patch release. I'm not familiar enough with PyO3 or Rust's packaging practices to propose a "fix" to CI.

Fwiw, the offending i32::rem_euclid was stabilised as const fn in 1.52.

Steps to Reproduce

Copied from CI logs:

nox > cargo check '--features=abi3 full' --all-targets --workspace --exclude=pyo3-ffi-check
  warning: /home/runner/work/pyo3/pyo3/examples/Cargo.toml: unused manifest key: example.0.doc-scrape-examples
      Checking chrono v0.4.25
      Checking pyo3-build-config v0.18.3 (/home/runner/work/pyo3/pyo3/pyo3-build-config)
     Compiling cssparser v0.27.2
  error: `core::num::<impl i32>::rem_euclid` is not yet stable as a const fn
     --> /home/runner/.cargo/registry/src/github.com-1ecc6299db9ec823/chrono-0.4.25/src/naive/internals.rs:118:20
      |
  118 |         let year = year.rem_euclid(400);
      |                    ^^^^^^^^^^^^^^^^^^^^
  
  error: aborting due to previous error
  
  error: could not compile `chrono`
  
  To learn more, run the command again with --verbose.
  warning: build failed, waiting for other jobs to finish...
  error: build failed
  nox > Command cargo check '--features=abi3 full' --all-targets --workspace --exclude=pyo3-ffi-check failed with exit code 101

Backtrace

No response

Your operating system and version

macOS 13.3.1

Your Python version (python --version)

3.10.6

Your Rust version (rustc --version)

1.48

Your PyO3 version

0.18.3 (main)

How did you install python? Did you use a virtualenv?

from source, active venv

Additional Info

No response

[davidhewitt]

Thanks - I've pushed #3194 which should hopefully resolve.