Add kex integration test for ed25519 server key #1320

Job	Run time
create_matrix	2s
Build wolfssl (ubuntu-latest, v5.9.0-stable)	6s
Build wolfssl (ubuntu-latest, v5.9.1-stable)	5s
Build wolfssl (ubuntu-latest, master)	7s
Build and test wolfsshd (ubuntu-latest, v5.9.0-stable)	2m 17s
Build and test wolfsshd (ubuntu-latest, master)	2m 20s
Build and test wolfsshd (ubuntu-latest, v5.9.1-stable)	2m 17s
	7m 14s

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