Stamp unity package version as 2.5.140

Merge pull request MessagePack-CSharp#1685 from MessagePack-CSharp/fi…

…x1586

Remove `long` to `int` truncation of stream position

Stamp unity package version as 2.5.124

Merge remote-tracking branch 'upstream/master' into develop

Merge pull request MessagePack-CSharp#1604 from neuecc/sourceGenerato…

…rImprovements

Enable P2P generic test

Merge pull request MessagePack-CSharp#1579 from AArnott/dev/andarno/c…

…ompilerWarningFix

Fix compiler warning that appears with VS 2022 Update 6 preview

Merge pull request MessagePack-CSharp#1575 from AArnott/fix1574

Fix PrimitiveObjectResolver's ability to read strings

Build stable 2.5 version

Merge pull request MessagePack-CSharp#1541 from neuecc/nrt

Last of the nullable ref annotations

Merge pull request MessagePack-CSharp#1529 from AArnott/fix1526

Remove dead constant