toolchain: gcc: add support for GCC 14

toolchain: gcc: add support for GCC 14

Deleted (upstreamed):
- 020-Include-safe-ctype.h-after-C-standard-headers-to-avo.patch [1]
- 021-libcc1-fix-vector-include.patch [2]

All other patches automatically rebased.

Note that selecting GCC 14, as of now, *will* result in build failures. The
packages that fail to build will be fixed as they're found. Thus, GCC 13.x is
the default, for the time being.

[1] https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=9970b576b7e4ae337af1268395ff221348c4b34a
[2] https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=5213047b1d50af63dfabb5e5649821a6cb157e33

Signed-off-by: Rui Salvaterra <rsalvaterra@gmail.com>