internal/rosa: respect preferred job count

This discontinues use of nproc, and also overrides detection behaviour in ninja.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/rosa/openssl.go

@@ -27,7 +27,7 @@ func (t Toolchain) newOpenSSL() (pkg.Artifact, string) {
 			{"openssldir", "etc/ssl"},
 		},
 		Check: []string{
-			`HARNESS_JOBS="$(expr "$(nproc)" '*' 2)"`,
+			"HARNESS_JOBS=" + jobsLE,
 			"test",
 		},
 	},