[docs] remove method toc icons

[ZacBlanco]

Description

Removes TOC icons from function definitions

Motivation and Context

See #22887 (comment)

Impact

Slight visual adjustment to page-level table of contents

Test Plan

N/A

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Release Notes

== NO RELEASE NOTE ==

[ZacBlanco]

@steveburnett try this one out locally and let me know if it works. Also, if there's anything else different with the new theme that bugs you, let me know and we can try to bundle the changes into this PR

[steveburnett]

@steveburnett try this one out locally and let me know if it works. Also, if there's anything else different with the new theme that bugs you, let me know and we can try to bundle the changes into this PR

Perfection! No other issues.

[steveburnett]

LGTM! (docs)

Pull branch, new docs build, looks great. Thanks for dealing with this so quickly!