Update dependencies in requirements.txt and remove obsolete testing files

- Upgraded `solana` from version 0.35.1 to 0.36.1 to support driftpy 0.8.39 and above
- Updated `anchorpy` from version 0.20.1 to 0.21.0 to ensure compatibility with driftpy and solana packages
- Increased `driftpy` version requirement from 0.8.35 to 0.8.40 to leverage recent enhancements and new markets (PAXG).
- Downgraded `rich` from version 14.0.0 to 10.14.0 to maintain compatibility with other libraries.
- Removed obsolete files: `TEST_CCXT_README.md`, `test_ccxt_requirements.txt`, and `test_ccxt.sh`, which are no longer needed for the project, streamlining the codebase.

Author: goldhaxx

backend/TEST_CCXT_README.md

@@ -6,12 +6,12 @@ numpy==1.26.4
 pandas==2.2.3
 python-dotenv==1.0.1
 pydantic==2.10.6
-solana==0.35.1
+solana==0.36.1
 streamlit==1.42.1
 uvicorn==0.34.0
 requests==2.32.3
 plotly==6.0.0
-anchorpy==0.20.1
-driftpy>=0.8.35
+anchorpy==0.21.0
+driftpy>=0.8.40
 ccxt==4.2.17
-rich>=14.0.0
+rich>=10.14.0