Fix type warning from ty

error[invalid-argument-type]: Argument to function `render_blocks` is incorrect
  --> tests/integration_test.py:56:30
   |
56 |         blocks=render_blocks(blocks),
   |                              ^^^^^^ Expected `list[Block]`, found `list[Header | Divider | MarkdownSection | MarkdownSectionFields | CodeBlock]`
   |
info: Function defined here
  --> ca_slack_block_kit/__init__.py:38:5
   |
38 | def render_blocks(blocks: list["Block"]) -> list[dict]:
   |     ^^^^^^^^^^^^^ --------------------- Parameter declared here
   |
info: `list` is invariant in its type parameter
info: Consider using the covariant supertype `collections.abc.Sequence`
info: For more information, see https://docs.astral.sh/ty/reference/typing-faq/#invariant-generics

Author: michelesr

ca_slack_block_kit/__init__.py

@@ -9,6 +9,7 @@
 """
 
 from abc import ABC, abstractmethod
+from collections.abc import Sequence
 from dataclasses import dataclass
 
 
@@ -35,7 +36,7 @@ class Emoji:
     SPARKLES = ":sparkles:"
 
 
-def render_blocks(blocks: list["Block"]) -> list[dict]:
+def render_blocks(blocks: Sequence["Block"]) -> list[dict]:
     """Render a list of Block objects into a list of dictionaries compatible with the Slack SDK client chat_postMessage function.
 
     Args:

docs.md

@@ -39,7 +39,7 @@ Various emojis for easy use with Slack messages.
 #### render_blocks
 
 ```python
-def render_blocks(blocks: list["Block"]) -> list[dict]
+def render_blocks(blocks: Sequence["Block"]) -> list[dict]
 ```
 
 Render a list of Block objects into a list of dictionaries compatible with the Slack SDK client chat_postMessage function.