Quickwin: Stop checking for curl support to add the mixpanel tracking part

[wordpressfan]

Description

Based on our discussion here:
https://group-onecom.slack.com/archives/C08EFCYRQ2X/p1752064231270499
and also here:
https://group-onecom.slack.com/archives/C08EFCYRQ2X/p1751569725073869?thread_ts=1751361983.496509&cid=C08EFCYRQ2X

We no longer depend on curl to send requests to mixpanel but depend mainly on WP HTTP API functions so even when curl is not there on the server we still are able to send the requests.

Type of change

• New feature (non-breaking change which adds functionality).
• Bug fix (non-breaking change which fixes an issue).
• Enhancement (non-breaking change which improves an existing functionality).
• Breaking change (fix or feature that would cause existing functionality to not work as before).
• Sub-task of #(issue number)
• Chore
• Release

Detailed scenario

What was tested

Validated that the plugin still works without any error and the tracking subscriber is loaded properly.

How to test

Testing now on a server without curl to see if it still works or not.

Technical description

Documentation

Mentioned above

New dependencies

No

Risks

No

Mandatory Checklist

Code validation

• I validated all the Acceptance Criteria. If possible, provide screenshots or videos.
• I triggered all changed lines of code at least once without new errors/warnings/notices.
• I implemented built-in tests to cover the new/changed code.

Code style

• I wrote a self-explanatory code about what it does.
• I protected entry points against unexpected inputs.
• I did not introduce unnecessary complexity.
• Output messages (errors, notices, logs) are explicit enough for users to understand the issue and are actionnable.

Unticked items justification

No tests for this part

Additional Checks

• In the case of complex code, I wrote comments to explain it.
• When possible, I prepared ways to observe the implemented system (logs, data, etc.).
• I added error handling logic when using functions that could throw errors (HTTP/API request, filesystem, etc.)

[codacy-production]

Coverage summary from Codacy

See diff coverage on Codacy

Coverage variation	Diff coverage
Report missing for 98943d51	❌ 0.00% (target: 50.00%)

Coverage variation details

	Coverable lines	Covered lines	Coverage
Common ancestor commit (98943d5)	Report Missing	Report Missing	Report Missing
Head commit (1f73692)	39809	17574	44.15%

Coverage variation is the difference between the coverage for the head and common ancestor commits of the pull request branch: <coverage of head commit> - <coverage of common ancestor commit>

Diff coverage details

	Coverable lines	Covered lines	Diff coverage
Pull request (#7495)	3	0	0.00%

Diff coverage is the percentage of lines that are covered by tests out of the coverable lines that the pull request added or modified: <covered lines added or modified>/<coverable lines added or modified> * 100%

See your quality gate settings    Change summary preferences

Footnotes

1. Codacy didn't receive coverage data for the commit, or there was an error processing the received data. Check your integration for errors and validate that your coverage setup is correct. ↩

[MathieuLamiot]

@wordpressfan Is this still needed?