Inform the users when their kernels become unsupported

[kneekoo]

Describe the bug
Until a few months ago, kernel 6.1 was shown as supported until 2027 in the kernel manager. Today I noticed it's unsupported. The problem is mintUpdate didn't notify me of this, and no longer offers updates for it. As my hardware is new enough that I can't use older kernels, this is bad.

Kernel 6.2 is now available in the kernel manager, but only supported until February 2024, so that's not a great alternative, but literally the only one available.

Screenshots

• this April (shown on top, in bold):
  

• today:
  

Expected behavior
mintUpdate should warn the users when unsupported kernels are in use. Even better, an upgrade path should be offered in the update manager, along with an explanation about what happened. And if upgrading to a non-LTS kernel, at least reassure the users that newer kernels will be available.

Considering I can only go with newer kernels for my hardware, the prospect of being unable to get kernel updates with the latest Linux Mint in just a few months is not great.

Distribution: Linux Mint 21.2 Cinnamon

Software version: 6.0.3

[Xmetalfanx]

This sounds like a good idea to me