fwupd 1.4.0 is now required

Hi all,

I've just merged the changes to the LVFS so that we refuse to supply
the firmware to fwupd versions < 1.4.5 which was released in 2020:
https://gitlab.com/fwupd/lvfs-website/-/commit/e9a0fbd20b28ae230ff283cbc0915d2ea065f161

Additionally ~1% of users using fwupd versions < 1.7.0 (released in
2021) will now be nagged to upgrade. The only branches getting
security fixes are 1.7.*, 1.8.x, 1.9x and of course main:
https://github.com/fwupd/fwupd/blob/main/SECURITY.md

For Debian, specifically this would affect Buster which is
oldoldstable and went EOL over a year ago. For RHEL-7 the workstation
product is EOL and EUS (Extended Update Support) is not available.
Nobody is testing firmware updates on these long-EOL versions, and
raising the required fwupd version allows us to delete quite a bit of
compatibility code and complexity.

Richard.