Switch telemetry library loading to plain require_once

[sanmai]

Description

Follow up to #5869. Let's remove the loop and use plain require_once.

Please only merge it after the library is fully deployed.

Pre-review checklist

Please make sure the items below have been covered before requesting a review:

• This change works and has been tested locally or in Codespaces (or has an appropriate fallback).
• This change works and has been tested on a sandbox.
• This change has relevant unit tests (if applicable).
• This change uses a rollout method to ease with deployment (if applicable - especially for large scale actions that require writes).
• This change has relevant documentation additions / updates (if applicable).
• I've created a changelog description that aligns with the provided examples.

Pre-deploy checklist

• VIP staff: Ensure any alerts added/updated conform to internal standards (see internal documentation).

Steps to Test

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 30.53%. Comparing base (04ceae6) to head (b4a844e).

Additional details and impacted files

@@              Coverage Diff              @@
##             develop    #5891      +/-   ##
=============================================
+ Coverage      30.51%   30.53%   +0.01%     
  Complexity      4811     4811              
=============================================
  Files            289      289              
  Lines          21173    21161      -12     
=============================================
  Hits            6461     6461              
+ Misses         14712    14700      -12     

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[rinatkhaziev]

needs to wait for 1 release cycle.

[sjinks]

@rinatkhaziev is this one good to go now?