Feature: Update to Qt 6.7.2

[mpogue2]

Fixes a bunch of bugs, and it's been released since June 19th, so it's probably OK to upgrade now.

[mpogue2]

No changes to the source code were required to move to Qt 6.7.2, so I've now moved to it for all development.

[mpogue2]

Running another 1 hour test, to check for glitches. If the rate is < 1 per hour, I probably won't see any difference. I'm continuing to do normal work while the test is running, too.

To clarify: if I see 0 glitches in 1 hour, the 90% confidence interval is [0.0, 3.0] glitches per hour, so if I ran the test for many more hours, 90% of the time the actual glitch rate would be between 0 and 3.0 . We can see that statistically, it would take a huge amount of testing to make this CI substantially smaller, and it will essentially never go to zero (that's just the nature of statistical testing like this).

[mpogue2]

Zero glitches in a second hour of testing, so:

• Qt6.7.1 = 1 hour, 0 glitches
• Qt6.7.2 = 1 hour, 0 glitches
• TOTAL = 2 hours, 0 glitches, 90% confidence interval = [0.0, 1.5] glitches per hour

Note that I am running plugged into a power supply. It's possible that running off battery alone would give different results. I'll have to try that sometime...

I'm hereby declaring that Qt6.7.1 works fine.