chore(#2787): minimum nvim version 0.9, replace 0.10 deprecated, enable deprecated warnings

[alex-courtis]

fixes #2787

• tag compat-nvim-0.8

[ZacharyRizer]

What needs to be done to get this merged @alex-courtis? I'd love to get that warning to go away every time nvim starts up on 0.10

[alex-courtis]

What needs to be done to get this merged @alex-courtis? I'd love to get that warning to go away every time nvim starts up on 0.10

Test please!

How are you seeing the warning? I didn't know nvim could do that...

[ZacharyRizer]

Maybe I misunderstood the point of this PR. I thought this was to fix the same issue that I tried to fix in this PR: #2781 which was then reverted back. My pr fixed this error from showing on start or 0.10 and 0.9 users (I thought at least).

But that message has come back since the above PR was reverted. Is this PR intended to fix the same issue?

[alex-courtis]

Maybe I misunderstood the point of this PR. I thought this was to fix the same issue that I tried to fix in this PR: #2781 which was then reverted back. My pr fixed this error from showing on start or 0.10 and 0.9 users (I thought at least).

Yes, I had to revert that one as it broke 0.10 dev versions. That method was added / mutated during the dev cycle.

It's the only vim api like that, all others were updated to use the new. We could do something like testing whether is_enabled is a function and use that only when 0.10 and the function is present.

But that message has come back since the above PR was reverted. Is this PR intended to fix the same issue?

Yes! That's what I'm after - how do you run that?

:checkhealth vim.deprecated yields:

==============================================================================
vim/deprecated: 

- ERROR No healthcheck found for "vim/deprecated" plugin.

[alex-courtis]

I've reinstated #2781 with an extra test: 46c2fb6

Please let me know how that goes.

[alex-courtis]

@ZacharyRizer I've not forgotten about you. We will get to the bottom of this:

• How are you running that deprecated health check?
• Why does it only pick up that one deprecated, not the other 26?