Move to .NET 9

[eduherminio]

• Bumps .NET version to .NET 9 and all dependencies
• Disables DATAS (⚡ Disable DATAS  #1111): enabled by default in .NET 9, see https://devblogs.microsoft.com/dotnet/performance-improvements-in-net-9/ and Move to .NET 9 #1108 (comment) for more info
• Disables CET (⚡ Disable CET #1112): https://learn.microsoft.com/en-us/dotnet/core/compatibility/interop/9.0/cet-support

[-3, 1] 8+0.08

Score of Lynx-net-9-no-cet-4299-win-x64 vs Lynx 4292 - main: 2745 - 2635 - 4416  [0.506] 9796
...      Lynx-net-9-no-cet-4299-win-x64 playing White: 2109 - 624 - 2165  [0.652] 4898
...      Lynx-net-9-no-cet-4299-win-x64 playing Black: 636 - 2011 - 2251  [0.360] 4898
...      White vs Black: 4120 - 1260 - 4416  [0.646] 9796
Elo difference: 3.9 +/- 5.1, LOS: 93.3 %, DrawRatio: 45.1 %
SPRT: llr 2.9 (100.2%), lbound -2.25, ubound 2.89 - H1 was accepted

Before disabling CET: perf regression

Score of Lynx-net-9-4284-win-x64 vs Lynx 4283 - main: 314 - 410 - 587  [0.463] 1311
...      Lynx-net-9-4284-win-x64 playing White: 246 - 106 - 304  [0.607] 656
...      Lynx-net-9-4284-win-x64 playing Black: 68 - 304 - 283  [0.320] 655
...      White vs Black: 550 - 174 - 587  [0.643] 1311
Elo difference: -25.5 +/- 14.0, LOS: 0.0 %, DrawRatio: 44.8 %
SPRT: llr -2.27 (-78.5%), lbound -2.25, ubound 2.89 - H0 was accepted

Score of Lynx-net-9-no-datas-4285-win-x64 vs Lynx 4283 - main: 3484 - 3630 - 5764  [0.494] 12878
...      Lynx-net-9-no-datas-4285-win-x64 playing White: 2611 - 909 - 2920  [0.632] 6440
...      Lynx-net-9-no-datas-4285-win-x64 playing Black: 873 - 2721 - 2844  [0.356] 6438
...      White vs Black: 5332 - 1782 - 5764  [0.638] 12878
Elo difference: -3.9 +/- 4.5, LOS: 4.2 %, DrawRatio: 44.8 %
SPRT: llr -2.27 (-78.6%), lbound -2.25, ubound 2.89 - H0 was accepted

Score of Lynx-net-9-no-datas-4285-win-x64 vs Lynx-net-9-4284-win-x64: 6549 - 6545 - 10616  [0.500] 23710
...      Lynx-net-9-no-datas-4285-win-x64 playing White: 4877 - 1642 - 5336  [0.636] 11855
...      Lynx-net-9-no-datas-4285-win-x64 playing Black: 1672 - 4903 - 5280  [0.364] 11855
...      White vs Black: 9780 - 3314 - 10616  [0.636] 23710
Elo difference: 0.1 +/- 3.3, LOS: 51.4 %, DrawRatio: 44.8 %
SPRT: llr -1.54 (-53.2%), lbound -2.25, ubound 2.89

Last validation:

Test  | net-9
Elo   | 2.52 +- 4.19 (95%)
SPRT  | 8.0+0.08s Threads=1 Hash=32MB
LLR   | 2.92 (-2.25, 2.89) [-5.00, 0.00]
Games | 11046: +3102 -3022 =4922
Penta | [244, 1276, 2420, 1322, 261]
https://openbench.lynx-chess.com/test/937/

[eduherminio]

DATAS (#404) will be enabled by default, it might be worth checking disabling it, although its performance improv should be negligible.

From Performance Improvements in .NET 9:

DATAS was introduced in .NET 8 and serves to narrow the gap between workstation and server GC, bringing server GC closer to workstation memory consumption. It dynamically scales how much memory is being consumed by server GC, such that in times of less load, less memory is being used.

While DATAS shipped in .NET 8, it was only on by default for Native AOT-based projects, and even there it still had some issues to be sorted. Those issues have now been sorted (...), such that in .NET 9, as of dotnet/runtime#103374, DATAS is now enabled by default for server GC.

If you have a workload where absolute best possible throughput is paramount and you’re ok with additional memory being consumed to enable that, you should feel free to disable DATAS, e.g. by adding this to your project file:

<GarbageCollectionAdaptationMode>0</GarbageCollectionAdaptationMode>

Back in the day the difference was minimal (#404) and it doesn't seem to be causing the initial perf issue here either.
Will disable it anyway.

Score of Lynx-net-9-no-datas-4285-win-x64 vs Lynx-net-9-4284-win-x64: 6437 - 6434 - 10439  [0.500] 23310
...      Lynx-net-9-no-datas-4285-win-x64 playing White: 4791 - 1612 - 5252  [0.636] 11655
...      Lynx-net-9-no-datas-4285-win-x64 playing Black: 1646 - 4822 - 5187  [0.364] 11655
...      White vs Black: 9613 - 3258 - 10439  [0.636] 23310
Elo difference: 0.0 +/- 3.3, LOS: 51.1 %, DrawRatio: 44.8 %
SPRT: llr -1.53 (-52.8%), lbound -2.25, ubound 2.89