(bash) regression: “TODO” in comments no longer highlighted

[wolfgang42]

Describe the issue

# This is a comment with a TODO item in it

should have the TODO highlighted as scope doctag, and used to, but no longer does as of d78749a (#3918).

Which language seems to have the issue?
bash

Are you using highlight or highlightAuto?
highlight

Sample Code to Reproduce

# This is a comment with a TODO item in it

Expected behavior
TODO is highlighted as doctag scope.

Additional context
I upgraded highlight.js and this stopped working. I bisected the problem to d78749a (#3918); in particular the relevant problem seems to be somewhere in this code:

highlight.js/src/languages/bash.js

Lines 41 to 52 in 85b2042

	const COMMENT = hljs.inherit(
	hljs.COMMENT(),
	{
	match: [
	/(^|\s)/,
	/#.*$/
	],
	scope: {
	2: 'comment'
	}
	}
	);

As far as I can tell, the scope: {2: 'comment'} is somehow screwing up the mode.contains.push({scope: 'doctag', ...}) detection in modes.js, but I don’t have a good enough grasp on highlight.js internals to really understand what's going on or how to fix it.

Test case which I expect to pass:

diff --git a/test/markup/bash/not-comments.txt b/test/markup/bash/not-comments.txt
--- a/test/markup/bash/not-comments.txt
+++ b/test/markup/bash/not-comments.txt
@@ -1,3 +1,5 @@
 echo asdf#qwert yuiop
 
 echo asdf #qwert yuiop
+
+# TODO: this *is* a comment
diff --git a/test/markup/bash/not-comments.expect.txt b/test/markup/bash/not-comments.expect.txt
index ab128642..0f57ee8b 100644
--- a/test/markup/bash/not-comments.expect.txt
+++ b/test/markup/bash/not-comments.expect.txt
@@ -1,3 +1,5 @@
 <span class="hljs-built_in">echo</span> asdf#qwert yuiop
 
 <span class="hljs-built_in">echo</span> asdf <span class="hljs-comment">#qwert yuiop</span>
+
+<span class="hljs-comment"># <span class="hljs-docstring">TODO:</span> this *is* a comment</span>

[wolfgang42]

(CC @iFreilicht and @joshgoebel as author/reviewer of previous PR.)