feat: update to latest sourcemod 1.11

[maxime1907]

Description

Add support for sourcemod 1.11 compilation by adding missing return statements

Motivation and Context

Compatibility with the latest 1.11-dev branch on the sourcemod repository

How Has This Been Tested?

In use for two months on https://nide.gg

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.