Do not test format specifiers not supported by musl
https://www.openwall.com/lists/musl/2024/02/28/5

--- a/test/date4.test
+++ b/test/date4.test
@@ -24,7 +24,7 @@
 }
 
 if {$tcl_platform(os)=="Linux"} {
-  set FMT {%d,%e,%F,%H,%k,%I,%l,%j,%m,%M,%u,%w,%W,%Y,%%,%P,%p,%U,%V,%G,%g}
+  set FMT {%d,%e,%F,%H,%I,%j,%m,%M,%u,%w,%W,%Y,%%,%p,%U,%V,%G,%g}
 } else {
   set FMT {%d,%e,%F,%H,%I,%j,%p,%R,%u,%w,%W,%%}
 }