Improve styling of list item's collapsing triangle #10506

Job	Run time
python-paths-filter	5s
cpp-paths-filter	6s
docs-paths-filter	5s
rust-paths-filter	7s
web-paths-filter	7s
Checks / Rerun lints	26s
Checks / Check if running codegen would produce any changes	1m 17s
Checks / Test Python Docs	29s
Checks / Check links	17s
Checks / Lint markdown	17s
Checks / Misc formatting	17s
Checks / Spell Check	5s
Update PR Body / Update PR body	16s
Deploy Landing Preview	0s
Python Checks	0s
C++ tests	0s
Rust Checks / Rust lints (fmt, check, clippy, tests, doc)	7m 17s
Minimum CLI Build / Set Config (linux-x64)	2s
Rust Checks / Test on macOS and Windows	0s
Build rerun_js / Build rerun_js	3m 6s
Build web viewer / Build web viewer	2m 58s
Minimum CLI Build / Build rerun-cli (ubuntu-latest-16-cores)	3m 44s
Upload Web / Upload web build to google cloud (wasm32 + wasm-bindgen)	13s
Save PR Summary / Create HTML summary for PR	36s
Minimum Wheel Build / Set Config (linux-x64)	3s
Minimum Wheel Build / Build Wheels (ubuntu-latest-16-cores)	1m 41s
Minimum Wheel Test / Set Config (linux-x64)	2s
Minimum Wheel Test / Test Wheels (ubuntu-latest-16-cores)	2m 33s
	26m 9s

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