refactor: [M3-6675] - Remove span from button component

[hasyed-akamai]

Description 📝

This PR removes the <span> component from the children of the Button component. This change will make it easier for test selectors to locate button elements without having to first find the <span> and then locate the closest button.

Changes 🔄

• Remove <span> from Button component children to simplify test selector targeting.

Target release date 🗓️

N/A

Verification steps

• Verify that button elements can now be found directly by test selectors without needing to reference the <span>.
• Ensure no existing functionality is broken and no regressions are introduced.
• Confirm all tests pass successfully.

Author Checklists

As an Author, to speed up the review process, I considered 🤔

👀 Doing a self review
❔ Our contribution guidelines
🤏 Splitting feature into small PRs
➕ Adding a changeset
🧪 Providing/improving test coverage
🔐 Removing all sensitive information from the code and PR description
🚩 Using a feature flag to protect the release
👣 Providing comprehensive reproduction steps
📑 Providing or updating our documentation
🕛 Scheduling a pair reviewing session
📱 Providing mobile support
♿ Providing accessibility support

• I have read and considered all applicable items listed above.

As an Author, before moving this PR from Draft to Open, I confirmed ✅

• All unit tests are passing
• TypeScript compilation succeeded without errors
• Code passes all linting rules

[linode-gh-bot]

Cloud Manager UI test results

🎉 500 passing tests on test run #3 ↗︎

❌ Failing	✅ Passing	↪️ Skipped	🕐 Duration
0 Failing	500 Passing	2 Skipped	112m 46s