Add License to all repos

[pnadolny13]

• [x] https://github.com/MeltanoLabs/tap-postgres - https://github.com/MeltanoLabs/tap-postgres/pull/138
• [x] https://github.com/MeltanoLabs/target-snowflake - https://github.com/MeltanoLabs/target-snowflake/pull/24
• [x] https://github.com/MeltanoLabs/target-duckdb - https://github.com/MeltanoLabs/target-duckdb/pull/2 (Pending switch to MIT https://github.com/MeltanoLabs/target-duckdb/pull/3)
• [x] https://github.com/MeltanoLabs/target-chromadb - https://github.com/MeltanoLabs/target-chromadb/pull/5 (Pending switch to MIT https://github.com/MeltanoLabs/target-chromadb/pull/6)
• [x] https://github.com/MeltanoLabs/tap-snowflake - https://github.com/MeltanoLabs/tap-snowflake/pull/22
• [x] https://github.com/MeltanoLabs/tap-duckdb - https://github.com/MeltanoLabs/tap-duckdb/pull/4 https://github.com/MeltanoLabs/tap-duckdb/pull/5
• [x] https://github.com/MeltanoLabs/tap-sqlalchemy - https://github.com/MeltanoLabs/tap-sqlalchemy/pull/4
• [x] https://github.com/MeltanoLabs/singer-sqlalchemy - ?
• [x] https://github.com/MeltanoLabs/map-gpt-embeddings - MIT https://github.com/MeltanoLabs/map-gpt-embeddings/pull/4
• [x] https://github.com/MeltanoLabs/gpt-meltano-demo - https://github.com/MeltanoLabs/gpt-meltano-demo/pull/1
• [ ] https://github.com/MeltanoLabs/sphinx-meltano - https://github.com/MeltanoLabs/sphinx-meltano/pull/17
• [x] https://github.com/MeltanoLabs/gpt-ext - https://github.com/MeltanoLabs/gpt-ext/pull/3
• [x] https://github.com/MeltanoLabs/evidence-ext - https://github.com/MeltanoLabs/evidence-ext/pull/40