refactor: remove data library option from cookiecutter

Remove the data_library choice (polars/pandas/none) as it's rarely
needed for Trail of Bits projects. This simplifies the template and
reduces unnecessary options during project creation.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: dguido

cookiecutter.json

@@ -23,11 +23,6 @@
         "none"
     ],
     "docstring_coverage": true,
-    "data_library": [
-        "polars",
-        "pandas",
-        "none"
-    ],
     "web_framework": [
         "fastapi",
         "none"

{{cookiecutter.project_slug}}/CLAUDE.md

@@ -70,20 +70,6 @@ Tests can also live beside source files as `test_*.py` or `*_test.py`.
 
 ## Key Libraries
 
-{%- if cookiecutter.data_library == "polars" %}
-- **Data processing**: Polars (preferred over pandas)
-  ```python
-  import polars as pl
-  df = pl.DataFrame({"col": [1, 2, 3]})
-  ```
-{%- elif cookiecutter.data_library == "pandas" %}
-- **Data processing**: Pandas
-  ```python
-  import pandas as pd
-  df = pd.DataFrame({"col": [1, 2, 3]})
-  ```
-{%- endif %}
-
 {%- if cookiecutter.web_framework == "fastapi" %}
 - **Web framework**: FastAPI (never use Flask)
   ```python
@@ -100,7 +86,6 @@ Tests can also live beside source files as `test_*.py` or `*_test.py`.
 ## Framework Preferences
 
 - **Web**: Always use FastAPI, never Flask
-- **Data**: Prefer Polars over Pandas for new code
 - **Async**: Use native async/await, not threading
 
 ## Common Patterns

{{cookiecutter.project_slug}}/pyproject.toml

@@ -20,11 +20,6 @@ classifiers = [
     "Programming Language :: Python :: 3",
 ]
 dependencies = [
-    {%- if cookiecutter.data_library == "polars" %}
-    "polars >= 0.20.0",
-    {%- elif cookiecutter.data_library == "pandas" %}
-    "pandas >= 2.0.0",
-    {%- endif %}
     {%- if cookiecutter.web_framework == "fastapi" %}
     "fastapi >= 0.100.0",
     "uvicorn[standard] >= 0.23.0",