Split out (ultra-)slow cargo doc jobs and run them only on nightly

[Wumpf]

What

• Fixes CI job sometime get stuck for a long time on some cargo doc steps #7387
  • well, sort of ;)

Checklist

• I have read and agree to Contributor Guide and the Code of Conduct
• I've included a screenshot or gif (if applicable)
• I have tested the web demo (if applicable):
  • Using examples from latest main build: rerun.io/viewer
  • Using full set of examples from nightly build: rerun.io/viewer
• The PR title and labels are set such as to maximize their usefulness for the next release's CHANGELOG
• If applicable, add a new check to the release checklist!
• If have noted any breaking changes to the log API in CHANGELOG.md and the migration guide

• PR Build Summary
• Recent benchmark results
• Wasm size tracking

To run all checks from main, comment on the PR with @rerun-bot full-check.

[github-actions]

Deployed docs

Commit	Link
32f1145	https://landing-415qh37e3-rerun.vercel.app/docs

[Wumpf]

drafted until ci run confirmed to be not awful

[Wumpf]

Mission accomplished!

 Timings:
44.56s 	 cargo check --quiet --locked --all-features
30.83s 	 cargo clippy --quiet --all-targets --all-features -- --deny warnings
26.10s 	 cargo install --quiet --locked cargo-deny
25.82s 	 cargo doc --quiet --no-deps --all-features --workspace --exclude rerun
19.03s 	 cargo clippy --quiet --all-features --target wasm32-unknown-unknown --target-dir target_wasm -p re_viewer -- --deny warnings
15.75s 	 cargo doc --quiet --document-private-items --no-deps --all-features --workspace --exclude rerun
10.89s 	 cargo check --quiet -p rerun --no-default-features
8.30s 	 cargo check --quiet --no-default-features -p custom_data_loader
7.72s 	 cargo check --quiet -p rerun --no-default-features --features sdk
5.98s 	 cargo check --quiet --no-default-features -p objectron
5.02s 	 cargo check --quiet --no-default-features -p log_file
4.53s 	 cargo check --quiet --no-default-features -p extend_viewer_ui
3.88s 	 cargo check --quiet --no-default-features -p template
3.57s 	 cargo check --quiet --no-default-features -p raw_mesh
3.46s 	 cargo check --quiet --no-default-features -p rerun-loader-rust-file
2.29s 	 cargo fmt --all -- --check
1.70s 	 cargo check --quiet --no-default-features -p minimal_serve
1.41s 	 cargo check --quiet --all-features -p extend_viewer_ui
1.37s 	 cargo deny --all-features --log-level error --target aarch64-apple-darwin check
1.31s 	 cargo check --quiet --no-default-features -p dna
1.19s 	 cargo deny --all-features --log-level error --target i686-pc-windows-gnu check
1.19s 	 cargo deny --all-features --log-level error --target x86_64-pc-windows-gnu check
1.18s 	 cargo deny --all-features --log-level error --target i686-unknown-linux-gnu check
1.18s 	 cargo deny --all-features --log-level error --target x86_64-unknown-linux-gnu check
1.18s 	 cargo deny --all-features --log-level error --target wasm32-unknown-unknown check
1.18s 	 cargo deny --all-features --log-level error --target i686-pc-windows-msvc check
1.18s 	 cargo deny --all-features --log-level error --target x86_64-unknown-linux-musl check
1.18s 	 cargo deny --all-features --log-level error --target x86_64-apple-darwin check
1.18s 	 cargo deny --all-features --log-level error --target x86_64-unknown-redox check
1.18s 	 cargo deny --all-features --log-level error --target x86_64-pc-windows-msvc check
0.59s 	 cargo check --quiet --no-default-features -p custom_space_view
0.59s 	 cargo check --quiet --no-default-features -p custom_store_subscriber
0.59s 	 cargo check --quiet --all-features -p custom_space_view
0.48s 	 cargo check --quiet --no-default-features -p clock
0.47s 	 cargo check --quiet --no-default-features -p minimal_options
0.47s 	 cargo check --quiet --no-default-features -p incremental_logging
0.44s 	 cargo check --quiet --no-default-features -p minimal
0.44s 	 cargo check --quiet --no-default-features -p stdio
0.44s 	 cargo check --quiet --no-default-features -p shared_recording
0.43s 	 cargo check --quiet --no-default-features -p spawn_viewer
0.42s 	 cargo check --quiet --all-features -p custom_store_subscriber
0.42s 	 cargo check --quiet --all-features -p custom_data_loader
0.38s 	 cargo check --quiet --all-features -p objectron
0.38s 	 cargo check --quiet --all-features -p raw_mesh
0.38s 	 cargo check --quiet --all-features -p incremental_logging
0.37s 	 cargo check --quiet --all-features -p clock
0.37s 	 cargo check --quiet --all-features -p minimal_options
0.37s 	 cargo check --quiet --all-features -p shared_recording
0.37s 	 cargo check --quiet --all-features -p log_file
0.37s 	 cargo check --quiet --all-features -p rerun-loader-rust-file
0.37s 	 cargo check --quiet --all-features -p minimal_serve
0.37s 	 cargo check --quiet --all-features -p minimal
0.37s 	 cargo check --quiet --all-features -p template
0.37s 	 cargo check --quiet --all-features -p dna
0.37s 	 cargo check --quiet --all-features -p stdio
0.37s 	 cargo check --quiet --all-features -p spawn_viewer
0.33s 	 cargo check --quiet --target wasm32-unknown-unknown --target-dir target_wasm -p re_renderer --examples