eng: Don't lint coverage output directory

[bwateratmsft]

This puts coverage/** into the lint ignores. It also takes main.[m]js out of it--I figured we should lint it since it is technically product code. Consequently, you might get lint errors when upgrading to this version.

[Copilot]

Pull request overview

Updates the shared engineering ESLint configuration to avoid linting generated code coverage artifacts, while re-enabling linting for main.js/main.mjs since they’re treated as product code in this package.

Changes:

• Add coverage/** to the global ESLint ignore list.
• Remove main.js and main.mjs from the global ESLint ignore list.
• Bump @microsoft/vscode-azext-eng version to 1.0.0-alpha.15 (and align lockfile).

Reviewed changes

Copilot reviewed 2 out of 3 changed files in this pull request and generated no comments.

File	Description
eng/src/eslint/eslintConfigs.ts	Adjusts global ignore patterns to skip coverage output and lint main.*js again.
eng/package.json	Version bump to 1.0.0-alpha.15.
eng/package-lock.json	Lockfile version fields updated to match 1.0.0-alpha.15.

Files not reviewed (1)

• eng/package-lock.json: Language not supported

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.