Move the supported platform set to net10.0 and net11.0

[gfraiteur]

Move PostSharp's supported platform set to net10.0 and net11.0 for the 2027.0 line.

• Update build definitions, packaging and build images for net11.0 #87
• Move the TeamCity test matrix to net10.0 and net11.0 #88
• Verify woven net11.0 assemblies under NativeAOT and ReadyToRun #89
• Confirm the new .NET 11 numeric types need no serializer change #90

Analysis: Documentation/DotNet11-CSharp15-Impact.md in postsharp/PostSharp.

— Claude for Gael