Fix: Add sqlalchemy.types.DOUBLE to dependency version specification

[bchoudhary6415]

This PR addresses the issue #165.

Introduction of a dependency on sqlalchemy.types.DOUBLE starting with version v0.4.2.

The DOUBLE type was introduced in SQLAlchemy version 2.0, as documented here:
https://docs.sqlalchemy.org/en/20/core/type_basics.html#sqlalchemy.types.Double

However, SQLAlchemy versions prior to 2.0 (e.g., 1.4.54) do not include the DOUBLE type in their types module:
https://github.com/sqlalchemy/sqlalchemy/blob/rel_1_4_54/lib/sqlalchemy/types.py

Currently, the project does not reflect this dependency on SQLAlchemy 2.0 or higher in several places:

The README states compatibility with SQLAlchemy versions between 0.7.3 and 2.0.x

The feedstock recipe does not specify a lower bound on the SQLAlchemy version

The setup.py requires only 'sqlalchemy>=0.7.3'

This PR updates the dependency specifications and documentation to explicitly require SQLAlchemy version 2.0 or newer, ensuring compatibility with the use of sqlalchemy.types.DOUBLE and avoiding runtime import errors.