test: try fix flaky test (#4429)

Not sure if this fixes #4390, but we now
reuse the same sandbox instead of recreating it
each time. We were failing a test where a spied method
was being called more than expected.

Signed-off-by: nkomonen <[email protected]>

Author: nkomonen-amazon

packages/toolkit/src/test/srcShared/fs.test.ts

@@ -24,12 +24,12 @@ describe('FileSystem', function () {
 
     before(async function () {
         fakeContext = await FakeExtensionContext.create()
+        sandbox = Sinon.createSandbox()
         await deleteTestRoot() // incase a previous test run failed to clean
     })
 
     beforeEach(async function () {
         await makeTestRoot()
-        sandbox = Sinon.createSandbox()
     })
 
     afterEach(async function () {