Bump langchain-text-splitters

Bumps [langchain-text-splitters](https://github.com/langchain-ai/langchain) from 0.3.4 to 0.3.9.
- [Release notes](https://github.com/langchain-ai/langchain/releases)
- [Commits](langchain-ai/langchain@langchain-text-splitters==0.3.4...langchain-text-splitters==0.3.9)

---
updated-dependencies:
- dependency-name: langchain-text-splitters
  dependency-version: 0.3.9
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

initiatives/agent_security_initiative/samples/frameworks/langgraph/multi_agent/requirements.txt

@@ -472,9 +472,9 @@ langchain-core==0.3.28 ; python_version >= "3.11" and python_version < "4.0" \
 langchain-openai==0.2.14 ; python_version >= "3.11" and python_version < "4.0" \
     --hash=sha256:7a514f309e356b182a337c0ed36ab3fbe34d9834a235a3b85cb7f91ae775d978 \
     --hash=sha256:d232496662f79ece9a11caf7d798ba863e559c771bc366814f7688e0fe664fe8
-langchain-text-splitters==0.3.4 ; python_version >= "3.11" and python_version < "4.0" \
-    --hash=sha256:432fdb39c161d4d0db16d61d38af068dc5dd4dd08082febd2fced81304b2725c \
-    --hash=sha256:f3cedea469684483b4492d9f11dc2fa66388dab01c5d5c5307925515ab884c24
+langchain-text-splitters==0.3.9 ; python_version >= "3.11" and python_version < "4.0" \
+    --hash=sha256:7cd1e5a3aaf609979583eeca2eb34177622570b8fa8f586a605c6b1c34e7ebdb \
+    --hash=sha256:cee0bb816211584ea79cc79927317c358543f40404bcfdd69e69ba3ccde54401
 langchain==0.3.13 ; python_version >= "3.11" and python_version < "4.0" \
     --hash=sha256:3d618a8e7e496704dc4407d224218ff28baf9416c1241e7bdcdd117e6c70daa8 \
     --hash=sha256:dd3549a28dc28b5d4769122b60fad0890aee86928d1bdbba3f9349d9f023315d