libstdc++: Report compilation error on formatting "%d" from month_last [PR120650]

libstdc++: Report compilation error on formatting "%d" from month_last [PR120650]

For month_day we incorrectly reported day information to be available, which lead
to format_error being thrown from the call to formatter::format at runtime, instead
of making call to format ill-formed.

	PR libstdc++/120650

libstdc++-v3/ChangeLog:

	* include/bits/chrono_io.h
	(formatter<chrono::month_day_last,_CharT>::parse): Call _M_parse with
	only Month being available.

(cherry picked from commit 190aaaaf077fe5f318e168a7a1e1aa57058f377e)