Update EF Core benchmark framework target to net11.0 (#2155)

The EF Core repo (dotnet/efcore main branch) has moved its projects to
target net11.0, but the benchmark scenario was still forcing net10.0.
This caused NETSDK1045 errors on the build agent since the .NET 10 SDK
cannot compile net11.0 projects.

Co-authored-by: Copilot <[email protected]>

Author: LoopedBard3

scenarios/efcore.benchmarks.yml

@@ -12,7 +12,7 @@ jobs:
       jobType: short
     arguments: --job {{jobType}} --filter {{filter}} --memory
     # force .NET version as the project currently uses a variable
-    framework: net10.0
+    framework: net11.0
     options:
       benchmarkDotNet: true