fix: dev: Fix -Wformat-truncation warning in totext_in_wks()

BIND 9 failed to build with GCC 16 at -O3: rendering a WKS record as text triggered a -Wformat-truncation error, which is fatal in developer builds. The port number is now printed with a 16-bit format specifier, so the compiler can see it always fits the output buffer.

Merge branch 'mnowak/fix-wks-format-truncation' into 'main'

See merge request isc-projects/bind9!12519