Use JSON import attribute (#694)

See
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/import/with

This requires bumping our target to ES2022 from ES2020. caniuse.com
shows that the adoption is roughly the same for the two targets.

src/js/data.ts

@@ -136,10 +136,9 @@ export function processRawCoreEntry(
 export default async function readData(options: {
   includeMultipleReforms: boolean;
 }): Promise<Record<PlaceId, ProcessedCoreEntry>> {
-  const rawData = (await import("../../data/core.json")) as unknown as Record<
-    PlaceId,
-    RawCoreEntry
-  >;
+  const rawData = (await import("../../data/core.json", {
+    with: { type: "json" },
+  })) as unknown as Record<PlaceId, RawCoreEntry>;
   return Object.fromEntries(
     Object.entries(rawData).map(([placeId, entry]) => [
       placeId,

tsconfig.json

@@ -3,8 +3,8 @@
     "noEmit": true,
     "allowImportingTsExtensions": true,
     "incremental": true /* Save .tsbuildinfo files to allow for incremental compilation of projects. */,
-    "target": "es2020" /* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */,
-    "module": "es2022" /* Specify what module code is generated. */,
+    "target": "ES2022" /* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */,
+    "module": "ESNext" /* Specify what module code is generated. */,
     "moduleResolution": "node" /* Specify how TypeScript looks up a file from a given module specifier. */,
     "resolveJsonModule": true /* Enable importing .json files. */,
     "allowSyntheticDefaultImports": true /* Allow 'import x from y' when a module doesn't have a default export. */,