vdk-duckdb: fix missing requirement

Install requirements need to be set in setup.py otherwise they will not be installed during pip install vdk-duckdb. 

requirements.txt is only for testing requirements.

Author: antoniivanov

projects/vdk-plugins/vdk-duckdb/requirements.txt

@@ -2,7 +2,6 @@
 # for requirements (dependencies) needed during and after installation of the plugin see (and update) setup.py install_requires section
 
 click
-duckdb
 pytest
 
 pytest

projects/vdk-plugins/vdk-duckdb/setup.py

@@ -17,7 +17,7 @@
     description="DuckDB Plugin for VDK.",
     long_description=pathlib.Path("README.md").read_text(),
     long_description_content_type="text/markdown",
-    install_requires=["vdk-core", "tabulate"],
+    install_requires=["vdk-core", "tabulate", "duckdb"],
     package_dir={"": "src"},
     packages=setuptools.find_namespace_packages(where="src"),
     # This is the only vdk plugin specific part