Replace Handlebars parser with Peggy grammar for @glimmer/syntax #13189

Job	Run time
tests / Perf script still works	19s
tests / Basic Test	14s
tests / package preparation test	1m 1s
tests / Linting	10s
tests / Type Checking (current version)	14s
tests / Blueprint Tests	0s
tests / Type Checking (other supported versions)	0s
tests / Browser Tests (Firefox)	0s
tests / matrix.name	0s
tests / Browserstack Tests (Safari, Edge)	0s
tests / Smoke tests with Deprecations Removed (Full Ember Apps)	0s
tests / Node.js Tests	0s
tests / Smoke tests (Full Ember Apps)	0s
Publish channel to s3	0s
Notify Discord	0s
Publish alpha from default branch	-1s
	1m 57s

Provide feedback