chore: drop unused prettier-plugin-pegjs

Prettier 3 does not auto-load plugins — they have to be listed under a
`plugins` key — and neither .prettierrc nor any package.json declares
one. The plugin was never loaded, so src/grammar.pegjs was not being
formatted by it either way.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

Author: tassoevan

packages/message-parser/package.json

@@ -55,7 +55,6 @@
 		"jest": "~30.2.0",
 		"npm-run-all": "^4.1.5",
 		"peggy": "4.1.1",
-		"prettier-plugin-pegjs": "~2.0.2",
 		"rimraf": "^6.0.1",
 		"tinybench": "^3.0.7",
 		"ts-loader": "~9.5.7",

yarn.lock

@@ -10023,7 +10023,6 @@ __metadata:
     jest: "npm:~30.2.0"
     npm-run-all: "npm:^4.1.5"
     peggy: "npm:4.1.1"
-    prettier-plugin-pegjs: "npm:~2.0.2"
     rimraf: "npm:^6.0.1"
     tinybench: "npm:^3.0.7"
     tldts: "npm:~6.1.86"
@@ -15027,15 +15026,6 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@types/node@npm:^20.5.6":
-  version: 20.19.43
-  resolution: "@types/node@npm:20.19.43"
-  dependencies:
-    undici-types: "npm:~6.21.0"
-  checksum: 10/cb060ea17ef9f1fc9d47cfb00098175b25fc6f6bae3c08a89ec7ba1be3353445ccf8af62d88c591e6413c09713f7705a71684a27ef01d2bccac4be96b00cacac
-  languageName: node
-  linkType: hard
-
 "@types/node@npm:~22.16.5":
   version: 22.16.5
   resolution: "@types/node@npm:22.16.5"
@@ -32190,16 +32180,6 @@ __metadata:
   languageName: node
   linkType: hard
 
-"prettier-plugin-pegjs@npm:~2.0.2":
-  version: 2.0.2
-  resolution: "prettier-plugin-pegjs@npm:2.0.2"
-  dependencies:
-    "@types/node": "npm:^20.5.6"
-    prettier: "npm:^3.0.2"
-  checksum: 10/418ae45f2c41acefbd44ddf78110cb95d95b16a3f2febb291ef6a2ef58987f86072885973dd963fa2f60516a1fd578d69fe2bd09ecc5a6697e381f5bd8c8a58d
-  languageName: node
-  linkType: hard
-
 "prettier@npm:^2.7.1":
   version: 2.8.8
   resolution: "prettier@npm:2.8.8"
@@ -32209,7 +32189,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"prettier@npm:^3.0.2, prettier@npm:~3.9.6":
+"prettier@npm:~3.9.6":
   version: 3.9.6
   resolution: "prettier@npm:3.9.6"
   bin: