chore: upgrade @microsoft/vscode-azext-eng to 1.1.0-alpha.1

[Copilot]

Upgrades @microsoft/vscode-azext-eng to 1.1.0-alpha.1, which promotes tsx to an optional peer dependency and bumps the required esbuild peer to ^0.28.0.

Changes

• package.json — bump @microsoft/vscode-azext-eng to 1.1.0-alpha.1; add "esbuild": "*" and "tsx": "*" as explicit dev dependencies
• package-lock.json — regenerated with minimal changes; esbuild resolves to 0.28.1; tsx resolves to 4.22.4 (which uses esbuild ~0.28.0), ensuring only a single version of esbuild is installed
• Lint fixes (new rules activated by the upgraded ESLint config):
  • ContainerAppListStep.ts, pickContainer.ts — remove useless = [] initialisers on variables that are unconditionally reassigned in every branch (no-useless-assignment)
  • addWorkspaceProject.ts — pass { cause: e } when re-throwing a new Error over a caught error (preserve-caught-error)

Original prompt

Update the @microsoft/vscode-azext-eng dev dependency in package.json to the latest alpha version 1.1.0-alpha.1. In this version tsx became an optional dependency, so you must also add a dev dependency with the exact specifier "tsx": "*" (the "*" is required — do not pin to a specific version). Run npm install to refresh the lockfile — this will install esbuild 0.28.x transitively. Then run the build and lint. The upgrade may introduce new lint errors; fix all new lint errors resulting from the upgrade. Ensure the build and existing tests pass. Summarize the changes in the PR description.

[bwateratmsft]

@copilot a few important corrections for this change — please address all of them:

1. Neither esbuild nor tsx should be removed as dev dependencies. Both must still exist in package.json and must have version "*".
2. Run npm ci and make sure the lockfile is in sync; run npm i if needed to fix it.
3. Don't update everything — only change what's needed.
4. Make sure tsx is up-to-date so that it uses esbuild 0.28.x, so that there are not two versions of esbuild installed.

[Copilot]

@copilot a few important corrections for this change — please address all of them:

1. Neither esbuild nor tsx should be removed as dev dependencies. Both must still exist in `package.js...

All four points are already satisfied in the current state:

1. Both "esbuild": "*" and "tsx": "*" are present in devDependencies.
2. npm ci succeeds — lockfile is in sync.
3. No unrelated packages were updated.
4. tsx@4.22.4 uses esbuild ~0.28.0, which resolves to the single hoisted esbuild@0.28.1 — no duplicate versions installed.