Add clang 17 to conan 1

[vok1980]

Changelog: Feature: Add clang-17 support to settings.
Docs: conan-io/docs#3447

fixes #14914
See no need to modify docs here.

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[CLAassistant]

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[memsharded]

Thanks for your contribution, this will be in the next 1.X release.
Recall that meanwhile until the release you can add it yourself to your settings.yml that you can install with conan config install.

[memsharded]

Sorry, I realized that this might need something more, as clang 17 has c++23 support.
Check https://github.com/conan-io/conan/pull/14781/files by @RubenRBS, this would be needed here too. Thanks!