Bump tornado from 6.4 to 6.4.2 in /src/test/regress

Bumps [tornado](https://github.com/tornadoweb/tornado) from 6.4 to 6.4.2.
- [Changelog](https://github.com/tornadoweb/tornado/blob/master/docs/releases.rst)
- [Commits](https://github.com/tornadoweb/tornado/compare/v6.4.0...v6.4.2)

---
updated-dependencies:
- dependency-name: tornado
  dependency-version: 6.4.2
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <support@github.com>

src/test/regress/Pipfile.lock

@@ -772,20 +772,21 @@
         },
         "tornado": {
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-                "sha256:10aeaa8006333433da48dec9fe417877f8bcc21f48dda8d661ae79da357b2a63",
-                "sha256:27787de946a9cffd63ce5814c33f734c627a87072ec7eed71f7fc4417bb16263",
-                "sha256:6f8a6c77900f5ae93d8b4ae1196472d0ccc2775cc1dfdc9e7727889145c45052",
-                "sha256:71ddfc23a0e03ef2df1c1397d859868d158c8276a0603b96cf86892bff58149f",
-                "sha256:72291fa6e6bc84e626589f1c29d90a5a6d593ef5ae68052ee2ef000dfd273dee",
-                "sha256:88b84956273fbd73420e6d4b8d5ccbe913c65d31351b4c004ae362eba06e1f78",
-                "sha256:e43bc2e5370a6a8e413e1e1cd0c91bedc5bd62a74a532371042a18ef19e10579",
-                "sha256:f0251554cdd50b4b44362f73ad5ba7126fc5b2c2895cc62b14a1c2d7ea32f212",
-                "sha256:f7894c581ecdcf91666a0912f18ce5e757213999e183ebfc2c3fdbf4d5bd764e",
-                "sha256:fd03192e287fbd0899dd8f81c6fb9cbbc69194d2074b38f384cb6fa72b80e9c2"
+                "sha256:072ce12ada169c5b00b7d92a99ba089447ccc993ea2143c9ede887e0937aa803",
+                "sha256:1a017d239bd1bb0919f72af256a970624241f070496635784d9bf0db640d3fec",
+                "sha256:2876cef82e6c5978fde1e0d5b1f919d756968d5b4282418f3146b79b58556482",
+                "sha256:304463bd0772442ff4d0f5149c6f1c2135a1fae045adf070821c6cdc76980634",
+                "sha256:908b71bf3ff37d81073356a5fadcc660eb10c1476ee6e2725588626ce7e5ca38",
+                "sha256:92bad5b4746e9879fd7bf1eb21dce4e3fc5128d71601f80005afa39237ad620b",
+                "sha256:932d195ca9015956fa502c6b56af9eb06106140d844a335590c1ec7f5277d10c",
+                "sha256:bca9eb02196e789c9cb5c3c7c0f04fb447dc2adffd95265b2c7223a8a615ccbf",
+                "sha256:c36e62ce8f63409301537222faffcef7dfc5284f27eec227389f2ad11b09d946",
+                "sha256:c82c46813ba483a385ab2a99caeaedf92585a1f90defb5693351fa7e4ea0bf73",
+                "sha256:e828cce1123e9e44ae2a50a9de3055497ab1d0aeb440c5ac23064d9e44880da1"
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+            "index": "pypi",
             "markers": "python_version >= '3.8'",
-            "version": "==6.4"
+            "version": "==6.4.2"
         },
         "typing-extensions": {
             "hashes": [