chore(deps): bump pytest to 9.0.3 (#36801)

CVE-2025-71176 (medium severity)

All are dev-only (test dependency group) — no impact on published
packages.

### Why syrupy was also bumped

syrupy 4.x (`<5.0.0`) constrains pytest to `<9.0.0`, blocking the CVE
fix. Widening to `<6.0.0` allows syrupy 5.x which supports pytest 9.x.

libs/langchain_v1/pyproject.toml

@@ -61,15 +61,15 @@ Reddit = "https://www.reddit.com/r/LangChain/"
 
 [dependency-groups]
 test = [
-    "pytest>=8.0.0,<10.0.0",
+    "pytest>=9.0.3,<10.0.0",
     "pytest-cov>=4.0.0,<8.0.0",
     "pytest-watcher>=0.2.6,<1.0.0",
-    "pytest-asyncio>=0.23.2,<2.0.0",
+    "pytest-asyncio>=1.3.0,<2.0.0",
     "pytest-socket>=0.6.0,<1.0.0",
     "pytest-xdist<4.0.0,>=3.6.1",
     "pytest-mock",
     "pytest-benchmark>=5.1.0,<6.0.0",
-    "syrupy>=4.0.2,<6.0.0",
+    "syrupy>=5.0.0,<6.0.0",
     "toml>=0.10.2,<1.0.0",
     "blockbuster>=1.5.26,<1.6.0",
     "langchain-tests",
@@ -93,7 +93,6 @@ test_integration = [
 ]
 
 [tool.uv]
-prerelease = "allow"
 constraint-dependencies = ["urllib3>=2.6.3", "pygments>=2.20.0"]
 
 [tool.uv.sources]