Where we already had a .NET 6 target, we just drop net5.0. Where .NET 5 was the latest target, we change it to target .NET 6.

This is because .NET 5 is no longer supported by Microsoft, so no one is expected to be using that runtime at this point.

MessagePack.Generator RollForward to Major

Drop net5.0 runtime targets

Bumps [Newtonsoft.Json](https://github.com/JamesNK/Newtonsoft.Json) from 10.0.3 to 13.0.1.
- [Release notes](https://github.com/JamesNK/Newtonsoft.Json/releases)
- [Commits](JamesNK/Newtonsoft.Json@10.0.3...13.0.1)

---
updated-dependencies:
- dependency-name: Newtonsoft.Json
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Bumps [Newtonsoft.Json](https://github.com/JamesNK/Newtonsoft.Json) from 12.0.3 to 13.0.1.
- [Release notes](https://github.com/JamesNK/Newtonsoft.Json/releases)
- [Commits](JamesNK/Newtonsoft.Json@12.0.3...13.0.1)

---
updated-dependencies:
- dependency-name: Newtonsoft.Json
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

…lizerBenchmark/Newtonsoft.Json-13.0.1

Bump Newtonsoft.Json from 12.0.3 to 13.0.1 in /benchmark/SerializerBenchmark

…/Newtonsoft.Json-13.0.1

Bump Newtonsoft.Json from 10.0.3 to 13.0.1 in /sandbox/Sandbox

Allocating 1MB buffers contribute to the large object heap and should be avoidable for applications that it is a problem for.

Add StringInterningFormatter.cs.meta for Unity

Add option to avoid large buffer allocations

…s commit by some unknown accident).

Merging

…with_MessagePackFormatterAttribute

Skip type collection if property has MessagePackFormatterAttribute

Revise the fix slightly

This has evidently been broken since I regressed it in 5c0220e.

Fix for "System.NotImplementedException: byref delegate" (second attempt)

Add non-generic serialize/deserialize perf tests

There was a bug, which produced "System.OverflowException: Arithmetic operation resulted in an overflow".

Fix OverflowException in SafeBitConverter.ToInt64