[13th Age Glorantha] Fix disabling number input field controls on Chrome

[speque]

Changes / Comments

The selectors used here are pseudo-elements, not pseudo-classes, so we need to use a double colon:

https://developer.mozilla.org/en-US/docs/Web/CSS/::-webkit-outer-spin-button

Before:

After:

I also added the quotes for consistency, as they are used in other similar selectors.

Roll20 Requests

Comments are very helpful for reviewing the code changes. Please answer the relevant questions below in your comment.

• [X] Does the pull request title have the sheet name(s)? Include each sheet name.
• [X] Is this a bug fix?
• [ ] Does this add functional enhancements (new features or extending existing features) ?
• [ ] Does this add or change functional aesthetics (such as layout or color scheme) ?
• [ ] If changing or removing attributes, what steps have you taken, if any, to preserve player data ?
• [ ] If this is a new sheet, did you follow Building Character Sheets standards ?

If you do not know English. Please leave a comment in your native language.