Support suggesting email as `login_hint` #3639

Job	Run time
Check frontend style	33s
Check the frontend for unused dependencies	25s
Run the frontend test suite	34s
Check schema	3m 45s
Compile test artifacts	4m 27s
Check Rust style	14s
Lint and test OPA policies	6s
Run `cargo deny` checks	42s
Run Clippy	2m 13s
Run test suite with Rust stable (2)	2m 15s
Run test suite with Rust stable (3)	2m 46s
Run test suite with Rust stable (1)	2m 32s
Tests done	4s
	20m 36s

Provide feedback