Update tinygo version used in tests

[jsocol]

Versions of tinygo before 0.31 do not have precompiled darwin-arm64
binaries. To continue using macos-latest runners, we need to update.

[Integralist]

Is this related to the CI error in #1187

[jsocol]

Is this related to the CI error in #1187

Yep! I haven't been able to find exactly when, but at some point last week it seems like macos-latest Actions runners switched architectures.

I wanted to double check before merging, though, that there are no other reasons we've been using 0.27.0? Are there any potential issues or unknowns we should validate?

[Integralist]

Probably just the first tinygo version that we could use when developing the feature.

If I check the default CLI configuration...
https://github.com/fastly/cli/blob/main/.fastly/config.toml#L15-L16

We can see that we set a minimum tinygo version of 0.28.x 🤔

[Integralist]

And for clarification, in case you were unfamiliar with this file:
https://github.com/fastly/cli/blob/main/DEVELOPMENT.md#fastlyconfigtoml

[jsocol]

Thanks! Just to double check my understanding, .fastly/config.toml ends up embedded in pkg/config.Static and the data ends up emitted for Go compute projects into the new project's fastly.toml, right? I wouldn't think we want to change the minimum tinygo version for WASI, but maybe it's OK to change the default for new fastly.toml? Should we do that in the same PR? Happy to add it, unless it deserves it's own write-up