[build] main *conceptually* targets .NET 10 (#1283)

Context: 356485e

`Java.Interop.dll` assembly version is now 10.0.

With 356485e significantly changing `generator` output, without a
corresponding `generator --lang-features` or equivalent switch to
revert behavior, it feels "safer" to bump the assembly version *now*
to reduce the likelihood of inadvertent assembly mixing.

(Not that I'm arguing that we *should* have such a flag.
We absolutely need to move away from requiring System.Reflection.Emit.)

GitInfo.txt

@@ -1 +1 @@
-9.0
+10.0