fix: resolve CI linting failures

- Removed unused imports (pathlib.Path, Schema, EnvVar, Optional)
- Fixed f-strings without placeholders in generator.py and validators.py
- Removed unused variables in generator.py
- Updated CI workflow to use correct project name (envschema)

envschema/cli.py

@@ -1,12 +1,9 @@
-"""CLI interface for EnvSchema."""
-
 import sys
-from pathlib import Path
 
 import click
 
 from envschema import __version__
-from envschema.schema import load_schema_from_file, Schema
+from envschema.schema import load_schema_from_file
 from envschema.core import validate_environment
 from envschema.generator import generate_env_example_to_file
 from envschema.formatters import format_result