docker: add gdb and valgrind to installed packages
I don't use valgrind very often (ever since ASan was created), but I'm
shocked I hadn't needed gdb before now.
@@ -28,6 +28,7 @@ RUN \
meson cmake \
'^clang-[0-9\.]+$' \
'^g(cc|\+\+)-[0-9\.]+$' \
+ gdb valgrind \
qemu binfmt-support qemu-user-static \
creduce screen htop parallel nano rsync strace \
npm libsleef-dev
