This change removes language server configuration from the default
languages.toml config for integration tests. No integration-tests
currently depend on the availability of a language server but if any
future test needs to, it may provide a language server configuration
by passing an override into the `test_syntax_conf` helper.
Language-servers in integration tests cause false-positive failures
when running integration tests in GitHub Actions CI. The Windows
runner appears to have `clangd` installed and all OS runners have
the `R` binary installed but not the `R` language server package.
If a test file created by `tempfile::NamedTempFile` happens to have a
file extension of `r`, the test will most likely fail because the
R language server will fail to start and will become a broken pipe,
meaning that it will fail to shutdown within the timeout, causing a
false-positive failure. This happens surprisingly often in practice.
Language servers (especially rust-analyzer) also emit unnecessary
log output when initializing, which this change silences.
`helix_view::apply_transaction` closes over `Document::apply` and
`View::apply` to ensure that jumplist entries are updated when a
document changes from a transaction. `Document::apply` shouldn't
be called directly - this helper function should be used instead.