chore: Track flagsmith-rust-sdk 3.1.1 (#8393)

Co-authored-by: flagsmith-engineering[bot] <flagsmith-engineering[bot]@users.noreply.github.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: 3 people

api/app_analytics/constants.py

@@ -111,6 +111,7 @@
         "2.1.1",
         "3.0.0",
         "3.1.0",
+        "3.1.1",
     ],
     "flagsmith-swift-ios-sdk": [
         "unknown",