Upgrade to jest 27 (#7699)

* use jest@27.4.0, replace jest-environment-jsdom-sixteen with jest-environment-jsdom

Signed-off-by: Kerry Archibald <kerrya@element.io>

* polyfill setImmediate

Signed-off-by: Kerry Archibald <kerrya@element.io>

* remove done from async test cases

* useRealTimers in test relying on promise flushing

Signed-off-by: Kerry Archibald <kerrya@element.io>

* remove jest environment file

Signed-off-by: Kerry Archibald <kerrya@element.io>

* replace ts-jest mocked with jest utils mocked

Signed-off-by: Kerry Archibald <kerrya@element.io>

test/utils/MegolmExportEncryption-test.js

@@ -117,10 +117,9 @@ cissyYBxjsfsAn
         });
 
         // TODO find a subtlecrypto shim which doesn't break this test
-        it.skip('should decrypt a range of inputs', function(done) {
+        it.skip('should decrypt a range of inputs', function() {
             function next(i) {
                 if (i >= TEST_VECTORS.length) {
-                    done();
                     return;
                 }
 
@@ -132,12 +131,12 @@ cissyYBxjsfsAn
                     return next(i+1);
                 });
             }
-            return next(0).catch(done);
+            return next(0);
         });
     });
 
     describe('encrypt', function() {
-        it('should round-trip', function(done) {
+        it('should round-trip', function() {
             const input =
                   'words words many words in plain text here'.repeat(100);
 
@@ -151,8 +150,7 @@ cissyYBxjsfsAn
                 );
             }).then((plaintext) => {
                 expect(plaintext).toEqual(input);
-                done();
-            }).catch(done);
+            });
         });
     });
 });