Accept negative numbers in INPUT.number

[felfert]

See #5145

This trivial fix for client-side input validation makes negative numbers valid again in INPUT.number fields. As mentioned by @benebsiny here, the regex was wrong before, but somehow never showed a visible malfunction in the browser before.

Proposed changelog entries

• Accept negative numbers in number input controls (regression in 2.274)

Proposed upgrade guidelines

N/A

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@mention

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[daniel-beck]

Based on #5145 (comment) there probably needs to be some further cleanup (numbers vs. integers), but this is a step in the right direction.

Untested.

[oleg-nenashev]

Needs a changelog entry.
We may need to backport it into the 2.277.x LTS line, it would be great to have a Jira issue for it

[oleg-nenashev]

We may merge it in 24 hours if there is no negative feedback. Please see the merge process documentation for more information about the merge process