Experimental Version Update & Steam Deck Verification Submission

Fellow railroad-builders! We just published a new experimental version on the experimental (and experimental-fna3d) branch.

Changelog 2.0-b4e4b9067 (compatible with production version):

• Improvement: Less obtrusive join discord message (hides after clicking join, no double usage with appearance change button anymore)
• Change: Linux build now uses FNA 22.0.7 as default

We also submitted this build for the Steam Deck verification and hope to get verified soon.