Typescript tests have started failing

[jtdavis777]

see https://github.com/google/flatbuffers/actions/runs/23508571696/job/69030965485?pr=8995

@bjornharrtell not sure what happened here - doesn't look like a regression in our code.

[bjornharrtell]

Hmm, perhaps it's running on latest TypeScript which was recently released and has some breaking changes. But that's wierd it supposed to be a locked version.