Bump sqlfluff from 0.6.2 to 0.6.4 in /dependencies (#1883)

Bumps [sqlfluff](https://github.com/sqlfluff/sqlfluff) from 0.6.2 to 0.6.4.
- [Release notes](https://github.com/sqlfluff/sqlfluff/releases)
- [Changelog](https://github.com/sqlfluff/sqlfluff/blob/main/CHANGELOG.md)
- [Commits](https://github.com/sqlfluff/sqlfluff/compare/0.6.2...0.6.4)

---
updated-dependencies:
- dependency-name: sqlfluff
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

dependencies/Pipfile.lock

@@ -1059,11 +1059,11 @@
         },
         "sqlfluff": {
             "hashes": [
-                "sha256:3070181751a093d83fdb802b65d8163d765e5d5b6c01f2440d702899f7c51734",
+                "sha256:923ac29b3c11857be73271c2c43f1306506752e9f6be0497ac26069d898f74c4",
-                "sha256:84eaa5257448eba36cbab06616de7a8e84c883ba03bfc984ea048e374299f64a"
+                "sha256:d265f334e1290d24aba5be88e880c016419f226eefda93fcdf361521fffcd089"
             ],
             "index": "pypi",
-            "version": "==0.6.2"
+            "version": "==0.6.4"
         },
         "stopit": {
             "hashes": [