ci(workflows): Arduino, Auto-close, and PlatformIO maintenance

[ZZ-Cat]

Overview

This Pull Request brings in some much needed maintenance updates to my wokrflows for Arduino build, Auto-close of stale issues, and PlatformIO build.

This Pull Request is still a work-in-progress.
Also, this is the only Pull Request to the Main-Trunk.
Everything else will be put to their relevant branches as per #90

[ZZ-Cat]

I just reinstated my Arduino workflow, and it returned the same error that @SB-JHL-B26 was talking about.

Now I know what they are referring to, I can get to the bottom of this.
It got past my checks, because a bug on Adafruit's end caused the build test to fail on something that they needed to fix, and at the time, I had to temporarily disable the Arduino check entirely. So, this little beauty slipped past my quality control undetected.
Now that the bug on Adafruit's end has been fixed, I have enabled the Arduino build check, only to be faced with the "No such file or directory" bug with CRSF for Arduino. As I said to SB-JHL-B26, this is very odd (and I am still puzzled about it, by the way).
But, now I know what to do and where to go, from here.

For the time being, I may temporarily disable the Arduino check altogether, until I can get it fixed in a separate Issue-Pull-Request combo, and go from there.

I changed my mind on 👆 that.
I will leave the Arduino check there and let it fail, so the Arduino tag on my README.md will show that the build is failing, to alert people that Arduino IDE support is currently broken.
I may need to issue a PSA in my Discussions about this, given its severity.

[ZZ-Cat]

Okay, I am bypassing my branch-protections to the Main-Trunk here, because I want to show that the Arduino build check is failing.
Tomorrow, I will issue a PSA about the broken Arduino IDE support.
This is pretty severe, and it underlines the point of why I don't disable my automations, even when one of them is bugged. Lesson learned: Wait for the devs of the actions to fix the bug they have on their end, rather than disabling the workflow on my end. 'Cause I was totally oblivious to this one, otherwise.
Given I take code security and reliability very seriously, this is one huge mea culpa.