Remove deprecated `text::format` export. #5791

Job	Run time
cargo clippy+test (gtk)	3m 29s
mdbook build	1m 44s
druid doctests	1m 8s
Docs (windows-latest)	2m 59s
cargo fmt	42s
Docs (macos-latest)	1m 0s
cargo clippy+test (windows-latest)	3m 52s
Docs (ubuntu-latest)	4m 25s
cargo test (wasm32)	2m 15s
cargo clippy+test (macos-latest)	3m 11s
cargo clippy+test (wayland)	2m 59s
cargo clippy+test (ubuntu-latest)	3m 10s
	30m 54s

Provide feedback