fix(deploy-script-support): Use versioned bundleSource

This change shifts from using the endowed bundleSource from agoric-cli
to using the version of bundleSource in the contract's lockfile.

Veryfing the integrity of a contract requires that the contract be
bundled consistently and consequently have a consistent hash for
verifying its integrity.
So, the version of bundleSource must be pinned in the contract's
lockfile and cannot vary based on the version of the agoric-cli that
happens to be installed on the developers' systems.

By having contracts pin a version of deploy-script-support,
they will have a consistent version of bundleSource.

packages/deploy-script-support/src/helpers.js

@@ -1,6 +1,7 @@
 // @ts-check
 import '@agoric/zoe/exported.js';
 import { E } from '@endo/far';
+import bundleSource from '@endo/bundle-source';
 
 import { makeInstall } from './install.js';
 import { makeOfferAndFindInvitationAmount } from './offer.js';
@@ -22,7 +23,7 @@ const ZOE_INVITE_PURSE_PETNAME = 'Default Zoe invite purse';
 export const makeHelpers = async (homePromise, endowments) => {
   const { zoe, wallet, scratch, board } = E.get(homePromise);
 
-  const { bundleSource, lookup } = endowments;
+  const { lookup } = endowments;
 
   const walletAdmin = E(wallet).getAdminFacet();
   const installationManager = E(walletAdmin).getInstallationManager();