Upgrade botan to 0.11 #1693

Job	Run time
Documentation (stable)	1m 6s
Validate external types appearing in public API	1m 39s
Documentation (nightly)	1m 10s
Check semver compatibility	3m 9s
build (macOS-latest, stable)	4m 3s
Build rustls-cert-gen as a standalone package	31s
build-windows	14m 32s
build (ubuntu-latest, stable)	6m 50s
Measure coverage	6m 52s
build (ubuntu-latest, beta)	7m 22s
build (ubuntu-latest, nightly)	7m 5s
build (ubuntu-latest, stable 7 months ago)	7m 10s
Format & clippy	6m 26s
	1h 7m 55s

Provide feedback