[Fix] CI: fix uv lock resolution and tiktoken test timeout

1. Cap requires-python to <3.14 — no deps ship 3.14 wheels yet, and
   uv's cross-version resolver fails on the Python 3.14 split.
2. Change exclude-newer from relative "30 days" to absolute "2026-04-10"
   so the lockfile stays reproducible. The relative date caused
   cryptography==46.0.7 (published April 8) to fall outside the window.
3. Parametrize test_eager_loading_env_var_values instead of looping —
   with xdist the 6 subprocess cases can run in parallel instead of all
   running sequentially on one worker (~13 min → ~2 min).
   Also removed redundant case variants (Yes/YES/On/ON) that test the
   same str_to_bool code path.

pyproject.toml

@@ -3,7 +3,7 @@ name = "litellm"
 version = "1.83.6"
 description = "Library to easily interface with LLM API providers"
 readme = "README.md"
-requires-python = ">=3.9"
+requires-python = ">=3.9, <3.14"
 license = "MIT"
 license-files = ["LICENSE"]
 authors = [
@@ -211,7 +211,7 @@ build-backend = "uv_build"
 [tool.uv]
 default-groups = ["dev"]
 required-version = "==0.10.9"
-exclude-newer = "30 days"
+exclude-newer = "2026-04-10"
 
 [tool.uv.sources]
 litellm-proxy-extras = { workspace = true }

tests/test_litellm/test_eager_tiktoken_load.py

@@ -55,23 +55,22 @@ def test_eager_loading_enabled():
     assert result.returncode == 0, f"Subprocess failed:\nstdout: {result.stdout}\nstderr: {result.stderr}"
 
 
-def test_eager_loading_env_var_values():
+@pytest.mark.parametrize("value", ["1", "true", "True", "TRUE", "yes", "on"])
+def test_eager_loading_env_var_values(value):
     """Test that various env var values enable eager loading"""
-    values = ["1", "true", "True", "TRUE", "yes", "Yes", "YES", "on", "On", "ON"]
-    for value in values:
-        result = _run_python(
-            """
-            import litellm
-            assert hasattr(litellm, "encoding"), "Encoding should be available"
-            encoding = litellm.encoding
-            tokens = encoding.encode("test")
-            assert len(tokens) > 0
-            """,
-            env_override={"LITELLM_DISABLE_LAZY_LOADING": value},
-        )
-        assert result.returncode == 0, (
-            f"Failed for value {value!r}:\nstdout: {result.stdout}\nstderr: {result.stderr}"
-        )
+    result = _run_python(
+        """
+        import litellm
+        assert hasattr(litellm, "encoding"), "Encoding should be available"
+        encoding = litellm.encoding
+        tokens = encoding.encode("test")
+        assert len(tokens) > 0
+        """,
+        env_override={"LITELLM_DISABLE_LAZY_LOADING": value},
+    )
+    assert result.returncode == 0, (
+        f"Failed for value {value!r}:\nstdout: {result.stdout}\nstderr: {result.stderr}"
+    )
 
 
 def test_lazy_loading_default():