feat: Replace date-fns with dayjs

[TrevorBurnham]

Description

This PR replaces the date-fns dependency with dayjs, a more lightweight alternative. This should not affect any functionality. The intent is purely to reduce bundle size and, secondarily, node_modules weight.

Estimated performance impact

For a production site that doesn't use date-fns outside of Cloudscape, this change should reduce the size of the minified JavaScript bundle by ~40 KB, enough to improve page load times by ~10ms for a typical user.

How has this been tested?

All unit tests are passing. I haven't been able to run the integration tests on my machine, so please let me know if there are any issues with those.

Review checklist

The following items are to be evaluated by the author(s) and the reviewer(s).

Correctness

• Changes include appropriate documentation updates.
• Changes are backward-compatible if not indicated, see CONTRIBUTING.md.
• Changes do not include unsupported browser features, see CONTRIBUTING.md.
• Changes were manually tested for accessibility, see accessibility guidelines.

Security

• If the code handles URLs: all URLs are validated through the checkSafeUrl function.

Testing

• Changes are covered with new/existing unit tests? ✅
• Changes are covered with new/existing integration tests? ✅

---

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 97.17%. Comparing base (59b27e4) to head (60c5338).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #3786   +/-   ##
=======================================
  Coverage   97.17%   97.17%           
=======================================
  Files         856      856           
  Lines       25241    25276   +35     
  Branches     8939     8969   +30     
=======================================
+ Hits        24527    24562   +35     
- Misses        665      708   +43     
+ Partials       49        6   -43     

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[pan-kot]

Hi @TrevorBurnham ,

There is one failing unit test:

FAIL src/internal/utils/date-time/__tests__/format-date-localized.test.ts
  ● formatDateLocalized › handles invalid date strings by falling back to Date constructor

    RangeError: Invalid time value

      39 |     year: 'numeric',
      40 |     day: 'numeric',
    > 41 |   }).format(date.toDate());
         |      ^
      42 |
      43 |   if (isDateOnly) {
      44 |     return formattedDate;

[TrevorBurnham]

@pan-kot Thanks! I've updated this branch.

[pan-kot]

@TrevorBurnham ,

There are integration tests failing with:

    Expected: "January 2018 — January 2018"
    Received: "December 2017 — December 2017"

[TrevorBurnham]

@pan-kot I've updated and rebased the branch. I've tried to address the integration test issue, but I'm unable to run those tests on my machine, so please kick off the CI build to verify the fix.

[TrevorBurnham]

I saw that the CI failed because the chart-components package has an implicit dependency on date-fns. I've submitted a small PR there to unblock this: cloudscape-design/chart-components#144