Update mypy requirement from ~=1.18.0 to >=1.18,<1.20

Updates the requirements on [mypy](https://github.com/python/mypy) to permit the latest version.
- [Changelog](https://github.com/python/mypy/blob/master/CHANGELOG.md)
- [Commits](python/mypy@v1.18.1...v1.19.0)

---
updated-dependencies:
- dependency-name: mypy
  dependency-version: 1.19.0
  dependency-type: direct:development
...

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

Author: dependabot[bot]

pyproject.toml

@@ -47,7 +47,7 @@ Issues = "https://github.com/atlanhq/atlan-python/issues"
 
 [dependency-groups]
 dev = [
-    "mypy~=1.18.0",
+    "mypy>=1.18,<1.20",
     "ruff~=0.14.5",
     "types-setuptools~=80.9.0.20250822",
     "pytest~=8.4.2",