🔧 refactor: Replace interface{} with any in type definitions

[mkmccarty]

No description provided.

[Copilot]

Pull request overview

This PR modernizes the Go codebase by replacing the legacy interface{} type with the more idiomatic any type alias (introduced in Go 1.18) across the src/ei package. This refactoring improves code readability without changing functionality.

• All map[string]interface{} type declarations replaced with map[string]any
• Changes are consistent across test files and implementation files
• No functional changes, purely a type alias update

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
src/ei/ei_units_test.go	Updated test case struct field type and all test case option maps to use any instead of interface{}
src/ei/ei_units.go	Updated FmtApprox function call to use map[string]any for consistency
src/ei/ei_research.go	Updated multiple FormatEIValue function calls to use map[string]any for consistency