Global variables not loaded into global scope

[dlh01]

Description of the bug

Since the plugin loader includes plugin files within a function, variables defined by plugins in what would normally be global scope are not actually globalized.

Steps To Reproduce

See internal discussion at https://l.alley.dev/636711d9c8.

Additional Information

See workaround previously implemented at https://l.alley.dev/c0cc8fb23c, which is derived from https://github.com/Automattic/vip-go-mu-plugins/blob/60780fee97674a77a9ada2b25ce6dd4b6ebbd583/vip-helpers/vip-utils.php#L1381-L1424.

[attackant]

I tried these approaches, all resulting in the error:

1. Using require_once in function scope
2. Using require instead of require_once
3. Using a closure with include
4. Using extract($GLOBALS) with eval
5. Manually declaring globals before evaluation
6. Using Closure::bind() to unbind from current context
7. Using output buffering with include
8. Including wp-includes/plugin.php first
9. Creating a temporary file for global scope execution

The core issue appears to be that we can't escape PHP's variable scoping rules within the class method, regardless of how we try to include the file.

Thinking we could use activate_plugin function?