1.6 is no longer LTS (#9605)

* 1.6 is no longer LTS

---------

Co-authored-by: Mosè Giordano <765740+giordano@users.noreply.github.com>

Author: PallHaraldsson

CONTRIBUTING.md

@@ -33,7 +33,7 @@ Other changes may be required on a case-by-case basis, depending on the success
 
 When building binary packages we have to deal with [several incompatibilities](https://docs.binarybuilder.org/stable/tricksy_gotchas/).
 As a general remark, when using GCC as compiler (which is default when targeting Linux and Windows platforms) try to use the ***oldest*** versions that is able to compile your code, which can be selected with the `preferred_gcc_version` keyword argument to the [`build_tarballs`](https://docs.binarybuilder.org/stable/reference/#BinaryBuilder.build_tarballs) function, especially for [C++ code](https://gcc.gnu.org/onlinedocs/libstdc++/manual/abi.html), this is the only way to get maximum compatibility.
-In any case, avoid using GCC 11+ when building C++, as that would be incompatible with Julia v1.6, the current Long Term Support version.
+In any case, avoid using GCC 11+ when building C++, as that would be incompatible with Julia v1.6.
 There are currently no such problems with LLVM (the default compiler framework used when targeting macOS and FreeBSD), so that you can generally use the latest version of LLVM available, which is already the default.
 
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