chore(test): move isolatedModules configuration

Jest started warning about this and says to move the option to
`tsconfig.json`, so I did.

Author: pbrisbin

jest.config.ts

@@ -1,8 +1,6 @@
 import { createDefaultPreset, type JestConfigWithTsJest } from "ts-jest";
 
-const presetConfig = createDefaultPreset({
-  isolatedModules: true,
-});
+const presetConfig = createDefaultPreset();
 
 const jestConfig: JestConfigWithTsJest = {
   ...presetConfig,

tsconfig.json

@@ -15,7 +15,8 @@
     "removeComments": true,
     "module": "NodeNext",
     "esModuleInterop": true,
-    "strict": true
+    "strict": true,
+    "isolatedModules": true
   },
   "include": ["./src/**/*"],
   "exclude": ["./src/**/*.test.ts"]