manuals: Audit/bump dates for last content change

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Ziaee <ziaee@FreeBSD.org>
Closes #17676

man/man4/spl.4

@@ -15,7 +15,7 @@
 .\"
 .\" Copyright 2013 Turbo Fredriksson <turbo@bayour.com>. All rights reserved.
 .\"
-.Dd August 24, 2020
+.Dd May 7, 2025
 .Dt SPL 4
 .Os
 .

man/man4/zfs.4

@@ -17,7 +17,7 @@
 .\" own identifying information:
 .\" Portions Copyright [yyyy] [name of copyright owner]
 .\"
-.Dd May 29, 2025
+.Dd August 14, 2025
 .Dt ZFS 4
 .Os
 .