testsuite: gfortran: Remove obsolete references to Solaris 9

Some gfortran tests still contain references to long-obsolete Solaris 9.

This patch removes them.

Tested on i386-pc-solaris2.11.

2024-02-13  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>

	gcc/testsuite:
	* gfortran.dg/fmt_en.f90 (dg-output): Don't xfail on
	?86-*-solaris2.9*.
	* gfortran.dg/fmt_en_rd.f90: Likewise.
	* gfortran.dg/fmt_en_rn.f90: Likewise.
	* gfortran.dg/fmt_en_ru.f90: Likewise.
	* gfortran.dg/fmt_en_rz.f90: Likewise.