[neon-notifications] Dev Required: fastfloat - 6.1.5

[Neon CI]

https://build.neon.kde.org/job/watcher_release_neon-packaging_fastfloat/25/display/redirect

#<Debian::UScan::DEHS::Package:0x00007f4b2b30c258 @name="fastfloat", @debian_uversion="6.1.1", @debian_mangled_uversion="6.1.1", @upstream_version="6.1.5", @upstream_url="https://github.com/fastfloat/fast_float/archive/refs/tags/v6.1.5.tar.gz", @status="Newer version available">