Update to the 20210213 snapshot of GCC 10.2.1.
Back port part of r565301 | gerald | 2021-02-15 from lang/gcc11-devel:
Explicitly build --without-zstd such that archivers/zstd isn't pulled in inadvertedly when present in the build system even though it is not an explicit dependency. [1]
PR: 253286 [1]