feat(svelte): add support for svelte5

[shfx]

Adding support for svelte5.

This change works for us but I need some additional eyes and hands to verify if this is what you might need to upgrade to svelte5. Keep in mind this PR is using somewhat legacy api that is there just to help migration and should be rewritten to "native" before they ditch it (somewhere around svelte6)

Closes #30278

[shfx]

@microsoft-github-policy-service agree

[github-actions]

Test results for "tests 1"

12 flaky

⚠️ [firefox-page] › tests/page/page-evaluate.spec.ts:403:3 › should throw for too deep reference chain @firefox-ubuntu-22.04-node18
⚠️ [webkit-library] › tests/library/browsercontext-proxy.spec.ts:27:3 › should work when passing the proxy only on the context level @webkit-ubuntu-22.04-node18
⚠️ [webkit-library] › tests/library/proxy.spec.ts:93:11 › should proxy local network requests › by default › localhost @webkit-ubuntu-22.04-node18
⚠️ [webkit-library] › tests/library/proxy.spec.ts:93:11 › should proxy local network requests › by default › link-local @webkit-ubuntu-22.04-node18
⚠️ [webkit-library] › tests/library/proxy.spec.ts:93:11 › should proxy local network requests › with other bypasses › link-local @webkit-ubuntu-22.04-node18
⚠️ [webkit-library] › tests/library/selector-generator.spec.ts:236:5 › selector generator › should use parent text @webkit-ubuntu-22.04-node18
⚠️ [webkit-library] › tests/library/tracing.spec.ts:28:5 › should collect trace with resources, but no js @webkit-ubuntu-22.04-node18
⚠️ [webkit-page] › tests/page/page-leaks.spec.ts:82:5 › click should not leak @webkit-ubuntu-22.04-node18
⚠️ [webkit-page] › tests/page/page-leaks.spec.ts:107:5 › fill should not leak @webkit-ubuntu-22.04-node18
⚠️ [webkit-page] › tests/page/page-leaks.spec.ts:161:5 › waitFor should not leak @webkit-ubuntu-22.04-node18
⚠️ [webkit-page] › tests/page/page-screenshot.spec.ts:345:5 › page screenshot › should work while navigating @webkit-ubuntu-22.04-node18
⚠️ [webkit-page] › tests/page/page-set-input-files.spec.ts:39:3 › should upload a folder @webkit-ubuntu-22.04-node18

37838 passed, 654 skipped
✔️✔️✔️

Merge workflow run.

[agg23]

There's a lot of diff here because of auto-formatting. Please remove these changes.

[mxschmitt]

I think we actually want to introduce ct-svelte4-vite to keep testing for vite4, wdyt @agg23

[agg23]

Agreed

[shfx]

Sure, I'll will try to do that today. Thanks for the input.