In the rare case when the key before `:` is an alias (e.g. `{*x : 4}`),
the space before `:` is required (although this requirement is not
enforced by PyYAML), the reason being that a colon can be part of an
anchor name. Consequently, this commit adapts the `colons` rule to avoid
failures when this happens.
See this comment from Tina Müller for more details:
https://github.com/adrienverge/yamllint/pull/550#discussion_r1155297373
b92fc9cb31