Un-range values creating (new) uncertainty following mirroring changes

What type of issue is this?

Incorrect support data (example: BrowserX says "86" but support was added in "40")

What information was incorrect, unhelpful, or incomplete?

Due to https://github.com/mdn/browser-compat-data/pull/24155, several features in web-features have newly uncertain Baseline dates. It looks like all of the affected features are caused by ranged values for Firefox (desktop) from the following keys:

• css.properties.display.table-caption
• css.properties.dominant-baseline (and descendants?)
• css.properties.background-size.auto
• css.properties.fill-opacity
• css.properties.stroke-opacity
• svg.global_attributes.fill-opacity
• svg.global_attributes.stroke-opacity

It would be nice to avoid these ranges, as they prevent the calculation of a single date for whole groups of keys.

What browsers does this problem apply to, if applicable?

No response

What did you expect to see?

Unranged values.

Did you test this? If so, how?

N/A

Can you link to any release notes, bugs, pull requests, or MDN pages related to this?

• https://github.com/mdn/browser-compat-data/pull/24155
• https://github.com/web-platform-dx/web-features/pull/2409#pullrequestreview-2488845296

Do you have anything more you want to share?

No response

MDN URL

No response

MDN metadata

No response

### Tasks
- [x] `css.properties.display.table-caption`
- [x] `css.properties.dominant-baseline` (and descendants?)
- [x] `css.properties.background-size.auto`
- [x] `css.properties.fill-opacity`
- [x] `css.properties.stroke-opacity`
- [x] `svg.global_attributes.fill-opacity`
- [x] `svg.global_attributes.stroke-opacity`

Start with the listed CSS and SVG compatibility-data keys, focusing on Firefox desktop ranges, and compare their history with PR #24155. Determine the correct unranged values and verify that the affected feature groups can produce a single Baseline date, using the web-features review link as context.