run fixup in prepare, not postprepare

'npm publish' runs 'npm prepare', but does _not_ run postprepare,
leading to a 'works on my machine' problem.

Via: microsoft/TypeScript#54546 (comment)

Author: isaacs

package.json

@@ -31,8 +31,7 @@
     "postversion": "npm publish",
     "prepublishOnly": "git push origin --follow-tags",
     "preprepare": "rm -rf dist",
-    "prepare": "tsc -p tsconfig.json && tsc -p tsconfig-esm.json",
-    "postprepare": "bash fixup.sh",
+    "prepare": "tsc -p tsconfig.json && tsc -p tsconfig-esm.json && bash fixup.sh",
     "pretest": "npm run prepare",
     "presnap": "npm run prepare",
     "test": "c8 tap",