Add custom job scheduling and dependency combiners

- Introduce `CombinedDependenciesJob` for efficient dependency handling and memory management
- Add `ScheduleCustom<T>` for user-defined job execution/free logic
- Refactor `JobInfo` and `JobDataPool<T>` for safer resource management and custom function support
- Improve SPMD extension type constraint formatting
- Update SPMD project content path and increment assembly versions
- Add unit tests for combined dependencies and custom jobs
- Remove `[Timeout]` from tests to prevent spurious failures
- Add TODO for future `WideLane` optimizations
- Replace legacy .sln with .slnx for better solution structure

Misaki.HighPerformance.Test/UnitTest/Jobs/TestJobs.cs

@@ -100,4 +100,14 @@ public unsafe struct IncrementJob : IJob
     {
         Interlocked.Increment(ref *pCounter);
     }
+}
+
+public unsafe struct CustomJob
+{
+    public int* value;
+
+    public static void Execute(ref CustomJob job, ref JobRanges jobRanges, ref readonly JobExecutionContext ctx)
+    {
+        *job.value += 1;
+    }
 }