sci-chemistry/gromacs: Fix compilation with gcc-13

Closes: https://bugs.gentoo.org/915694
Signed-off-by: Pacho Ramos <pacho@gentoo.org>

sci-chemistry/gromacs/files/gromacs-2021-cstdint-include.patch

@@ -0,0 +1,12 @@
+# https://bugs.gentoo.org/915694
+# Not needed for newer branches, that greatly refactored the code
+--- a/src/gromacs/utility/flags.h~	2023-01-31 12:45:46.000000000 +0100
++++ b/src/gromacs/utility/flags.h	2023-10-16 10:15:24.087340444 +0200
+@@ -42,7 +42,7 @@
+  */
+ #ifndef GMX_UTILITY_FLAGS_H
+ #define GMX_UTILITY_FLAGS_H
+-
++#include <cstdint>
+ namespace gmx
+ {

sci-chemistry/gromacs/gromacs-2021.7-r1.ebuild

@@ -88,6 +88,7 @@ RESTRICT="!test? ( test )"
 PATCHES=(
 	"${FILESDIR}/${PN}-2021-musl-stdint.patch"
 	"${FILESDIR}/${PN}-2021-cuda-detection.patch"
+	"${FILESDIR}/${PN}-2021-cstdint-include.patch"
 )
 
 if [[ ${PV} != *9999 ]]; then