Remove unused instructions re: review of "Needs Approval" flag for post

The "Moderator Instructions" asset post includes instructions for using the review interface for each of the types of
automatically generated flags. One such type is the "Needs Approval" flag for posts. Although many of the equivalent
"Needs Approval" flag have been received for user accounts, not a single "Needs Approval" flag has been received for a
post in the two years since Arduino Forum was migrated to the Discourse framework that produces these flags.

Since the instructions for this flag type serve no purpose (and were never even validated against the actual forum
behavior), they are hereby removed.

Author: per1234

content/categories/staff/moderation/_topics/moderator-instructions/1.md

@@ -21,7 +21,6 @@ For an overview of the Discourse moderation system, see the **[Discourse Moderat
     - [Post flagged as "Something Else"](#post-flagged-as-something-else)
   - [Automated system-submitted flags](#automated-system-submitted-flags)
     - ["Needs Approval" flag for account](#needs-approval-flag-for-account)
-    - ["Needs Approval" flag for post](#needs-approval-flag-for-post)
     - [Akismet flagged post](#akismet-flagged-post)
     - ["flag_sockpuppets" flag](#flag_sockpuppets-flag)
 - [Guides](#guides)
@@ -168,25 +167,6 @@ Please note that Arduino has a firm policy against deleting any accounts, so you
 1. Click the **<kbd>Approve User</kbd>** button.
    **ⓘ** This is done to clear the flag in a manner compliant with [Arduino's user account policies](https://forum.arduino.cc/t/about-user-account-deletion-and-user-content-deletion/627095). It does not affect the suspension.
 
-<a name="needs-approval-flag-for-post"></a>
-
-#### ["Needs Approval" flag for post](#needs-approval-flag-for-post)
-
-This flag is created by `@system` when a post is detected as possibly malicious. The post must be reviewed by a moderator.
-
-<a name="if-the-post-is-benign"></a>
-
-##### [If the post is benign](#if-the-post-is-benign)
-
-1. Click the **<kbd>Approve Post</kbd>** button.
-
-<a name="if-the-post-is-malicious"></a>
-
-##### [If the post is malicious](#if-the-post-is-malicious)
-
-1. Suspend the user account, [following these instructions](#suspend-an-account)
-1. Click the **<kbd>Reject Post</kbd>** button.
-
 ---
 
 <a name="akismet-flagged-post"></a>