sysutils/slurm-wlm: Update 25.11.5 → 26.05.1

Changelog:
https://github.com/SchedMD/slurm/blob/slurm-26-05-1-1/CHANGELOG/slurm-26.05.md

• Remove unnecessary GUI_CONFIGURE_OFF and S2N_CONFIGURE_OFF - GUI_CONFIGURE_ENABLE and S2N_CONFIGURE_WITH cover them.
• Fix warnings from portclippy.
• Fix detection of the s2n in configure.
• Refresh patches.

PR: 295969
Sponsored by: UNIS Labs
Co-authored-by: Vladimir Druzenko <vvd@FreeBSD.org>
MFH: 2026Q2

(cherry picked from commit 8beaafa1d988794ad2ecec04169259a8145091c0)