build: install husky in prepare script instead of postinstall

With typicode/husky#890, the recommended way to install husky is in the
`prepare` script instead of the `postinstall`. This commit moves
the husky installation to the `prepare` script to align with the new
recommendation.

package.json

@@ -13,7 +13,7 @@
     "yarn": ">= 1.0.0"
   },
   "scripts": {
-    "postinstall": "husky install && node tools/postinstall/apply-patches.js && ngcc --properties module main --create-ivy-entry-points && node tools/postinstall/update-ngcc-main-fields.js",
+    "postinstall": "node tools/postinstall/apply-patches.js && ngcc --properties module main --create-ivy-entry-points && node tools/postinstall/update-ngcc-main-fields.js",
     "build": "node ./scripts/build-packages-dist.js",
     "build-docs-content": "node ./scripts/build-docs-content.js",
     "dev-app": "ibazel run //src/dev-app:devserver",
@@ -48,7 +48,8 @@
     "integration-tests:size-test": "bazel test //integration/size-test/...",
     "check-mdc-tests": "ts-node --project scripts/tsconfig.json scripts/check-mdc-tests.ts",
     "check-mdc-exports": "ts-node --project scripts/tsconfig.json scripts/check-mdc-exports.ts",
-    "check-tools": "yarn tsc --project tools/tsconfig-ci.json"
+    "check-tools": "yarn tsc --project tools/tsconfig-ci.json",
+    "prepare": "husky install"
   },
   "version": "12.0.0-next.5",
   "dependencies": {