## TPL: {fmt}

`{fmt}` library is now included in VTK as a third-party modules. This enables
VTK developers to use `{fmt}` for formatting strings.

The minimum external version of the `{fmt}` library has been to set to 8.1.0 which is an unreleased version.
The required PR from 8.1.0 is https://github.com/fmtlib/fmt/pull/2432.
