ValidSigil parsing behaves differently than sorbet sigil parsing

[jakebrady5]

Bug Description

The ValidSigil cop considers any valid sigil value followed by any non-word non-whitespace character to be valid. Sorbet does not. This conflict causes the ValidSigil cop to be overly permissive of functionally invalid sigil values.

Practical Example

A sample file began with this sigil:

# typed: false # rubocop:todo Sorbet/StrictSigil

A similar regex bug in spoom caused spoom to erroneously bump the sigil to:

# typed: true# rubocop:todo Sorbet/StrictSigil

This new true# sigil is functionally ignored by Sorbet, but does not cause a rubocop error despite being an invalid sigil value.