Upgrade to .NET 9.0 (#128) #304

Job	Run time
Timestamp	10s
Test StringEnum Trimmed	55s
Test Cloud Framework	2m 24s
Build macOS Shim	51s
Build Windows Shim	1m 27s
Build Linux Pass 1	6m 37s
Build macOS Pass 1	5m 16s
Build Windows Pass 1	6m 54s
Build Linux Shim	42s
Build macOS UEFS	1m 41s
Build Windows UEFS	3m 32s
Build and Test Libraries on Linux	7m 21s
Build Libraries on macOS	5m 23s
Build and Test Libraries on Windows	9m 24s
Build Windows Pass 2	7m 22s
Build Linux Pass 2	6m 25s
Build macOS Pass 2	4m 48s
Publish UET Container	20s
Publish to GitHub	1m 2s
Publish UEFS Container	14s
Publish UET Container (with Wine)	35s
Publish to NuGet	55s
Test Schema Generation	0s
	1h 14m 18s

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