chore: upgrade dependencies (202604)

[mzanoni]

https://trello.com/c/2DIEa93P/19836-recurring-task-development-webcomponents-check-package-dependencies

Summary

• Upgraded direct devDependencies in packages/web-components where newer stable versions were installable: @microsoft/api-extractor ^7.58.7, @typescript-eslint/eslint-plugin ^8.59.0, @typescript-eslint/parser ^8.59.0, dotenv ^17.4.2, rollup ^4.60.2, typescript ^6.0.3, typescript-lit-html-plugin ^0.9.1, and vite ^8.0.9.
• Kept comparator-ranged runtime dependencies unchanged: @lit/context >=1.1.6 <2.0.0 and lit >=3.3.1 <4.0.0.
• Added TypeScript compatibility config in packages/web-components/tsconfig.json so the upgraded compiler still accepts the current setup: ignoreDeprecations: "6.0" plus explicit mocha and node ambient types.
• Kept eslint on ^9.39.4 instead of @latest because the current latest eslint-plugin-import and eslint-plugin-promise peer ranges still stop at ESLint 9.
• Left @relewise/client unchanged because it is a peerDependency; npm outdated reports 2.23.1 available versus the current minimum >= 2.22.0.

Validation

• npm run build (in packages/web-components): passed
• npm run build:types (in packages/web-components): passed
• npm run test (in packages/web-components): failed in tests/popular-products.test.ts

Notes

• The failing test path uses integrationTestRelewiseOptions() and makes live API requests. In this environment it returned 404 / fetch failures against the configured Relewise integration values, so the validation gap appears environment/API-related rather than dependency-resolution-related.
• npm outdated still reports eslint behind @latest for the compatibility reason above, @relewise/client behind latest because peer dependencies were not auto-upgraded, and typescript-lit-html-plugin reporting an unusual Latest value of 0.9.0 while 0.9.1 is installed.