Specify package manager version in frontend project configuration

This is necessary for Dependabot updates to work properly.

frontend/apps/remark42/package.json

@@ -25,6 +25,7 @@
     "node": ">=16.15 <=17.*",
     "pnpm": "7.*"
   },
+  "packageManager": "pnpm@7.33.7",
   "dependencies": {
     "@github/markdown-toolbar-element": "^2.1.1",
     "@github/text-expander-element": "^2.2.2",

frontend/package.json

@@ -17,6 +17,7 @@
     "type-check:api": "turbo run type-check --filter=@remark42/api",
     "lint:api": "turbo run lint --filter=@remark42/api"
   },
+  "packageManager": "pnpm@7.33.7",
   "devDependencies": {
     "husky": "^8.0.1",
     "lint-staged": "^13.0.3",

frontend/packages/api/package.json

@@ -29,6 +29,7 @@
     "type-check": "tsc --noEmit",
     "lint-staged:lint": "eslint --fix --ext .cjs,.mjs,.ts"
   },
+  "packageManager": "pnpm@7.33.7",
   "devDependencies": {
     "@types/node": "^18.0.5",
     "@typescript-eslint/eslint-plugin": "^5.33.1",

site/package.json

@@ -10,6 +10,7 @@
 		"node": ">=20.11.1",
 		"yarn": ">=1.22"
 	},
+  "packageManager": "yarn@1.22.22",
 	"scripts": {
 		"start": "npm-run-all dev",
 		"dev": "npm-run-all -l clean build:css -p dev:css dev:11ty",