eslintrc rules may be invalid

[glasnt]

Discovered as part of unrelated changes: the rule to ignore missing imports is n/no-missing-imports, not node/no-missing-imports.

The .estlintrc.json inherits from gts, and uses module source, so the rule may never be used anyway, but it would be useful to confirm the configuration is correct and update it if required.

[glasnt]

It may have been a correct rule (possibly, cite: https://github.com/mysticatea/eslint-plugin-node/blob/master/docs/rules/no-missing-import.md) but it also may not be a mainline eslint rule anyway.

[glasnt]

It appears that the "eslint-plugin-n" module is used by gts, defining rules with the "n/" prefix.

This repo may have previously used the "eslint-plugin-node", which uses "node/" prefixes.