Add index schema 2.1 with delta support - #6523

`unbackfilled` is not a recognized word (unrecognized-spelling)

`recased` is not a recognized word (unrecognized-spelling)

`case insensitive` matches a line_forbidden.patterns rule: Should be `case-(in)sensitive` - `\bcase (?:in|)sensitive\b` (forbidden-pattern)

`updatetracking` is not a recognized word (unrecognized-spelling)

`Recased` is not a recognized word (unrecognized-spelling)

`NEWPC` is not a recognized word (unrecognized-spelling)

`newcmd` is not a recognized word (unrecognized-spelling)

`OLDPC` is not a recognized word (unrecognized-spelling)

`oldcmd` is not a recognized word (unrecognized-spelling)

`diffed` is not a recognized word (unrecognized-spelling)

Skipping `.github/workflows/issue-closure-recommendation.lock.yml` because it could not be parsed file within time limit (slow-file)

Skipping `.github/workflows/duplicate-surfacing.lock.yml` because it could not be parsed file within time limit (slow-file)

Line matches candidate pattern (assign regex) `= /[^*].*?(?:[a-z]{3,}|[A-Z]{3,}|[A-Z][a-z]{2,}).*/[gi]?(?=\W|$)` (candidate-pattern)