Revert css-loader back to 1.0.0

What does this MR do?

Reverts the css-loader back to 1.0.0 that was recently updated in !17560 (merged)

Closes #32902 (closed)

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Before	After (in this MR)

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation created/updated or follow-up review issue created
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content