Move type:module declaration into package.json.

matrix-js-sdk is built into ECMAScript modules, and we should declare it as
such. See https://nodejs.org/api/packages.html#type. Failure to do so causes
problems for javascript projects attempting to build against matrix-js-sdk: see #4347.

Previously, we did this as part of the package.json switcheroo, but that is
unnecessarily fragile.

matrix-react-sdk, element-web, etc are unaffected by this, because they use the
typescript files directly, by importing `matrix-js-sdk/src/...`.

package.json

@@ -31,6 +31,7 @@
     "keywords": [
         "matrix-org"
     ],
+    "type": "module",
     "main": "./src/index.ts",
     "browser": "./src/browser-index.ts",
     "matrix_src_main": "./src/index.ts",

scripts/release/pre-release.sh

@@ -12,6 +12,3 @@ do
         jq ".$i = .matrix_lib_$i" package.json > package.json.new && mv package.json.new package.json && yarn prettier --write package.json
     fi
 done
-
-# Ensure that "type": "module" is present
-jq '.type = "module"' package.json > package.json.new && mv package.json.new package.json && yarn prettier --write package.json

scripts/switch_package_to_release.cjs

@@ -12,10 +12,6 @@ async function main() {
         }
     }
 
-    // matrix-js-sdk is built into ECMAScript modules. Make sure we declare it as such.
-    // See https://nodejs.org/api/packages.html#type.
-    pkgJson["type"] = "module";
-
     await fsProm.writeFile(PKGJSON, JSON.stringify(pkgJson, null, 2));
 }