feat: support Angular template parser 21 and 22

[rdlabo]

Summary

• support @angular-eslint/template-parser 21 and 22 through an explicit peer dependency range
• keep parser 21.4 as the repository development baseline
• test packed-package installation and CLI execution in clean parser 21/ESLint 8 and parser 22/ESLint 9 consumers
• document how consumers select the parser major matching their Angular ESLint version
• raise the minimum runtime, CI jobs, Node types, and build target to Node.js 22

Why a peer dependency

The parser is loaded at runtime, but its major also carries an ESLint peer requirement. A regular ^21 || ^22 dependency makes npm select parser 22 even in ESLint 8 projects and can fail with ERESOLVE. Letting the consuming project select parser 21 or 22 avoids that conflict and ensures the collector uses the project's Angular template parser generation.

Validation

• parser 21.4.0: 68 unit tests passed
• parser 22.1.0: 68 unit tests passed
• clean packed-package install: parser 21.4.0 + ESLint 8.57.1
• clean packed-package install: parser 22.1.0 + ESLint 9.39.2
• packaged CLI smoke test is included for both combinations
• parser 22.1.0 successfully scanned the linked Angular 22 seatkeep/app without changing src/use-icons.ts
• npm run lint
• Node 22-targeted npm run build

The dependency and CI design passed an independent OSS-style review after the initial forced-install approach was rejected and removed.