hint users to update nightly on ICEs of outdated nightly

[matthiaskrgr]

From time to time we get reports of regressions that have already been fixed since several days, but the user uses a nightly that is 1-2 weeks old for example.

We could probably make nightly somewhat self-aware and make it:
grab the current date and compare it to its own version string
calculate when $current_version was released (iirc the time when the master-> nightly promotion happens can be found on the forge somewhere) and add maybe 6 to 12 hours as buffer.
If $current_version.release_timestamp is older than $current_time + 24 hours + buffer and nightly crashes, add a hint to perhaps update to the user but only iff we are on the master/nightly channel!

could look like this:

note: it seems this 'rustc 1.76.0-nightly (d86d65bbc 2023-12-10)' is outdated, nightly 2023-12-11 should have been released in the meantime. 
note: please consider running `rustup update nightly` to update the nightly channel and checking if this problem still persists.

note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md

note: please attach the file at `/tmp/im/rustc-ice-2023-12-11T16_34_58-2325463.txt` to your bug report

We could also consider hiding/adapting the we would appreciate a bug report line in case we detected a potentially outdated nightly.