Remove Docassemble core dependency from install_requires

[nonprofittechy]

Summary

Remove the docassemble.webapp>=1.4.54 packaging dependency from install_requires.

Why

This package is being installed into Docassemble servers that already provide the Docassemble core stack. Keeping a broad docassemble.webapp>=... dependency allows pip to resolve Docassemble core packages from PyPI during managed package installs.

In a live Docassemble-managed install test, that dependency caused the resolver to walk into older core releases from PyPI, including docassemble.base==1.7.0 and docassemble.demo==1.7.0, instead of preserving the server's installed 1.9.2 core stack.

This dependency appears to have originally been used as a minimum-version guard for older Docassemble servers, but at this point it is creating upgrade risk for current servers. Removing the core dependency lets Docassemble treat its own core packages as part of the platform rather than something this extension should ask pip to resolve.

Scope

This changes packaging metadata only. Runtime code is unchanged.

Verification

• python3 setup.py egg_info succeeds after this change
• managed install testing against a live Docassemble server showed the resolver problem described above