cad/irsim: adopt and update 9.7.116 => 9.7.118

• Take maintainership
• Flavourise with 3 flavours: lite, scheme (default) and tcl

+ Add LICENSE_FILE
+ Workaround building Tcl with clang17+

See https://github.com/RTimothyEdwards/irsim/issues/7

• Use localbase:ldflags via USES
• Improve pkg-descr
• Lint Makefile, sort stances

Changelog: https://github.com/RTimothyEdwards/irsim/releases/tag/9.7.118

PR: 284856