[Component amendment]: <CTA Block> Add CSS pseudo element for the single right-pointing angle quotation mark (›)

## [Component/pattern to amend](https://vanillaframework.io/docs/patterns/cta-block)

## Context

Our link text CTAs use the single right-pointing angle quotation mark (›) at the end. Screen readers may read this out so [our CTAs](https://vanillaframework.io/docs/patterns/cta-block) sound like “ contact us single right-pointing angle quotation mark”. I suggest updating the CSS:

.p-cta-link::after {
content: ' ›';
margin-left: 0.5rem;
}

Then this is properly coded as a styling element.

Review the CTA Block pattern documentation and locate the `.p-cta-link` styles. Start by checking how the link’s trailing angle mark is currently rendered; done means the mark is supplied through the requested CSS pseudo-element styling rather than link text, with the CTA appearance preserved.

Written by the indexing model from the issue text.