coreos/user-patches: Drop patches for sys-devel/gcc

We are updating to gcc 12, where the issue should not be present any
more.

sdk_container/src/third_party/coreos-overlay/coreos/user-patches/sys-devel/gcc/0001-constexpr.patch

@@ -1,14 +0,0 @@
-The constexpr keyword is missing for a function that was invoked from
-another constexpr function. Add the missing keyword.
-
---- a/libstdc++-v3/src/c++17/memory_resource.cc	2022-12-09 22:33:43.000000000 -0000
-+++ b/libstdc++-v3/src/c++17/memory_resource.cc	2023-01-25 13:14:24.025359063 -0000
-@@ -603,7 +603,7 @@
-     void* pointer = nullptr;
-     aligned_size<min> _M_size;
- 
--    size_t size() const noexcept
-+    constexpr size_t size() const noexcept
-     {
-       if (_M_size.value == size_t(-1)) [[unlikely]]
- 	return size_t(-1);

sdk_container/src/third_party/coreos-overlay/coreos/user-patches/sys-devel/gcc/README.md

@@ -1,6 +0,0 @@
-Drop `0001-constexpr.patch` when not applicable any more. It's a weird
-issue, because building the same version of the compiler worked fine
-before. Maybe some patch from gcc patches is at fault here. Didn't
-investigate in hope that the issue is ephemeral. Some newer version of
-gcc is already marked as stable for both amd64 and arm64 in Gentoo, so
-this patch will most likely be dropped next week.