Bump version of VSCode used in tests

[movermeyer]

What are you trying to accomplish?

The i18n-ally tests are failing, since the source.vue files are being given the language identifier of plaintext (the default for unknown languages).

There is an override in test/fixtures/vue/.vscode/settings.json, but that is ignored unless vue is a known identifier.

Previously, i18n-ally used the johnsoncodehk.volar extension to add recognition of the vue language identifier. At some point, johnsoncodehk.volar was renamed to vue.volar. But vue.volar cannot be installed on VSCode v1.52.0:

Installing extensions...
Installing extension 'vue.volar' v1.5.4...
Server returned 404
Failed Installing Extensions: vue.volar

What approach did you choose and why?

The most straightforward fix is to bump the version of VSCode used in the tests to a more modern one.

What should reviewers focus on?

These tests wil break once again in the future if/when vue.volar can no longer be installed on v1.77. But I don't have a nicer solution at this time.

Other options include:

• Create an otherwise empty extension that registers the vue identifier, and use that
  • A minimal extension is less likely to break with a future version of VSCode.
• Having i18n-ally itself register the vue identifier

The impact of these changes

CI will pass again. 🙌

[kibertoad]

@movermeyer Mac is still failing.

[terales]

@kibertoad it's a flaky test -- worked well after merge: