fix(gemini): annotate alias set as Final, drop narrative comments

Addresses review feedback: the module constant now carries the `Final`
annotation required by LIT010, and the explanatory comments are folded
into the existing docstring so the source keeps to the repository's
comment convention.

litellm/llms/vertex_ai/gemini/vertex_and_google_ai_studio_gemini.py

@@ -106,11 +106,7 @@ else:
     StreamingChoices = Any
 
 
-# Google's rolling aliases, which always resolve to the newest release of each
-# tier and today serve Gemini 3.x. They carry no version number, so they must be
-# listed explicitly for Gemini 3 feature detection to see them.
-# https://ai.google.dev/gemini-api/docs/models
-GEMINI_ROLLING_LATEST_ALIASES = frozenset(
+GEMINI_ROLLING_LATEST_ALIASES: Final[frozenset[str]] = frozenset(
     {
         "gemini-flash-latest",
         "gemini-flash-lite-latest",
@@ -279,20 +275,14 @@ class VertexGeminiConfig(VertexAIBaseConfig, BaseConfig):
         - gemini-3.1-pro-preview, gemini-3.1-flash, gemini-3.1-flash-lite-preview
         - gemini-3.5-flash
         - Any future Gemini 3.x models
-        - The rolling `-latest` aliases, which Google keeps pointed at the
-          newest release of each tier and which currently serve Gemini 3.x.
-
-        The `-latest` aliases are matched by exact name rather than by an
-        `endswith("-latest")` suffix check, because versioned names such as
-        `gemini-2.5-flash-native-audio-latest` also end in `-latest` and are
-        not Gemini 3.
+        - GEMINI_ROLLING_LATEST_ALIASES, which resolve to Gemini 3.x and carry
+          no version number of their own. Matched by exact name, since
+          versioned names such as `gemini-2.5-flash-native-audio-latest` also
+          end in `-latest` yet are not Gemini 3
         """
         # Check for Gemini 3 models
         if "gemini-3" in model:
             return True
-        # Rolling aliases carry no version in the name, so the substring check
-        # above cannot see them. Strip any provider prefix (`gemini/`,
-        # `vertex_ai/`) before comparing.
         return model.split("/")[-1] in GEMINI_ROLLING_LATEST_ALIASES
 
     @staticmethod

tests/test_litellm/llms/vertex_ai/gemini/test_vertex_and_google_ai_studio_gemini.py

@@ -2275,8 +2275,6 @@ def test_is_gemini_3_or_newer():
     # Edge cases
     assert VertexGeminiConfig._is_gemini_3_or_newer("") == False
 
-    # Rolling `-latest` aliases resolve to Gemini 3.x and carry no version in
-    # the name, so they must be detected explicitly.
     assert VertexGeminiConfig._is_gemini_3_or_newer("gemini-flash-latest") == True
     assert VertexGeminiConfig._is_gemini_3_or_newer("gemini-flash-lite-latest") == True
     assert VertexGeminiConfig._is_gemini_3_or_newer("gemini-pro-latest") == True
@@ -2287,7 +2285,6 @@ def test_is_gemini_3_or_newer():
         VertexGeminiConfig._is_gemini_3_or_newer("vertex_ai/gemini-pro-latest") == True
     )
 
-    # A versioned name that merely ends in `-latest` is not Gemini 3.
     assert (
         VertexGeminiConfig._is_gemini_3_or_newer(
             "gemini-2.5-flash-native-audio-latest"
@@ -2339,7 +2336,6 @@ def test_thought_signature_fallback_for_rolling_latest_alias():
             "thoughtSignature" in part for part in parts
         ), f"expected a thought signature for {model}"
 
-    # Pre-Gemini-3 models must not gain a signature they never needed.
     parts = convert_to_gemini_tool_call_invoke(message, model="gemini-2.5-flash")
     assert not any("thoughtSignature" in part for part in parts)