[ML-KEM] serialize sk #1100

Job	Run time
extract	2m 57s
extract	2m 57s
extract	2m 46s
extract-header-only	3m 9s
extract-header-only	3m 9s
extract-header-only	2m 55s
diff	19s
diff	5s
diff	9s
build (macos-latest)	5m 8s
build (macos-latest)	5m 8s
build (macos-latest)	5m 54s
build (ubuntu-latest)	19m 56s
build (ubuntu-latest)	19m 56s
build (ubuntu-latest)	9m 1s
build (windows-latest)	2m 56s
build (windows-latest)	2m 56s
build (windows-latest)	3m 23s
diff-header-only	5s
diff-header-only	4s
diff-header-only	4s
build-header-only (macos-latest)	18s
build-header-only (macos-latest)	18s
build-header-only (macos-latest)	27s
build-header-only (ubuntu-latest)	22s
build-header-only (ubuntu-latest)	22s
build-header-only (ubuntu-latest)	24s
build-header-only (windows-latest)	1m 3s
build-header-only (windows-latest)	1m 3s
build-header-only (windows-latest)	1m 42s
	1h 38m 56s

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