Remove redundant dependencies and enforce exact pinning

[seroperson]

Closes #1264

Summary

Audited pyproject.toml against the actual import graph and tightened both the dep list and the pinning policy.

Eight redundant packages dropped:

• bittensor-cli, bittensor-commit-reveal: zero direct imports anywhere, and neither is a transitive of bittensor 10.0.1
• bittensor-wallet: already a transitive of bittensor; explicit pin only risked fighting the resolver
• levenshtein, python-dotenv: zero direct imports; env vars are already read via os.environ
• fastapi, uvicorn from [debug]: already transitives of bittensor; the explicit pins were downgrading what bittensor wanted
• pytz: only consumer was CHICAGO_TZ + parse_github_timestamp_to_cst in gittensor/validator/utils/datetime_utils.py, which chore: integrate pre-push vulture dead-code scanner #1253 found is dead code

Every remaining direct dep is now exact-pinned (==), replacing the previous mix of ==, >=, and bare names. The lockfile and pyproject.toml now agree on a single resolution by construction.

Held bittensor at 10.0.1: bumping needs more involved changes and is better addressed in a separate PR to avoid widening scope. The same for tree-sitter and tree-sitter-language-pack.

Removed	Why
bittensor-cli==9.17.0 (runtime)	No import bittensor_cli anywhere; not a transitive of bittensor 10.0.1
bittensor-commit-reveal==0.4.0 (runtime)	No import bittensor_commit_reveal anywhere; not a transitive
bittensor-wallet==4.0.0 (runtime)	Already a transitive of bittensor; the explicit pin only fought the resolver
levenshtein==0.27.3 (runtime)	Zero direct imports (Levenshtein, levenshtein, rapidfuzz) anywhere
python-dotenv==1.2.1 (runtime)	load_dotenv() never called; env vars read via os.environ.get already
pytz==2025.2 (runtime)	Only consumer was dead code (see below)
fastapi==0.110.1 (from [debug])	Already a transitive of bittensor; explicit pin was downgrading it
uvicorn==0.32.0 (from [debug])	Already a transitive of bittensor; explicit pin was downgrading it
CHICAGO_TZ constant in gittensor/validator/utils/datetime_utils.py	Only used inside parse_github_timestamp_to_cst (also dead)
parse_github_timestamp_to_cst() function	Never called anywhere in gittensor/, neurons/, tests/, scripts/ (per #1253)
import pytz in datetime_utils.py	No remaining consumer after CHICAGO_TZ removed

Type of Change

• Bug fix
• New feature
• Refactor
• Documentation
• Other

Testing

• Tests added/updated
• Manually tested