Bump h2 from 0.3.21 to 0.3.24 in /tests/hello-tls #379

Job	Run time
Check	32s
MSRV	2m 35s
Test Suite (ubuntu-latest, stable)	4m 55s
Clippy	33s
Test Suite (ubuntu-latest, nightly)	4m 47s
Rustfmt	6s
Test Suite (macos-latest, stable)	10m 51s
spellcheck	9s
Test Suite (macos-latest, nightly)	10m 52s
Test Suite (windows-latest, stable)	8m 12s
Test Suite (windows-latest, nightly)	8m 18s
	51m 50s

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