style: use parentheses for Less mixin invocation across all .less files

[dxu429]

Clever Coding Standards Agreement

• Author and Review Statement, "We agree this code adheres to our Clever Global Coding Standards and other applicable Coding Standards"

Jira:

https://clever.atlassian.net/browse/DD-7212

Overview:

Less 4.x deprecates the old bare mixin invocation syntax (.myMixin;) in favor of the explicit call syntax with parentheses (.myMixin();). This PR updates every .less file in the repo — both source components under src/ and documentation examples under docs/ — to use the parenthesized call form. The genBorderRadius.js code-generation script is also updated so that future runs of the generator emit the correct syntax.

Changes included:

• src/**/*.less: All mixin calls in component styles updated to use () syntax
• docs/**/*.less: All mixin calls in documentation example styles updated to use () syntax
• src/less/border_radius.less: Composite border-radius mixin calls updated
• genBorderRadius.js: Generator script updated to emit () syntax for future regenerations

Related PRs:
https://github.com/Clever/sd2/pull/10388
https://github.com/Clever/clever-ui/pull/285

Screenshots/GIFs:

No visual changes expected — this is a pure syntax update with identical compiled output.

Testing:

• Unit tests
• Manual tests:
  • Chrome
  • Safari
  • IE11

Roll Out:

• Before merging:
  • Updated docs
  • Bumped version in package.json
    • Breaking change?
      • If it is a beta component run npm version minor
      • If the component is not in beta run npm version major
    • New component or backward-compatible component feature change? Run npm version minor
    • Only changing documentation? All good. Skip this step.
  • After creating a new component, make sure to add it to the Components List in ComponentsView.jsx. To do so:
    • Add a screenshot of the component in docs/assets/img with the format <COMPONENT URL LINK>.png
• After merging:
  • Deployed updated docs (make deploy-docs)
  • Posted in #eng if I made a breaking change to a beta component