refactor: Timestamp parsing to handle timezone information

[KellianL]

Description

This PR fixes the timestamp parsing in Report._extract_timestamp() to properly handle ISO 8601 timestamps that include timezone information.

Solution

• Replaced datetime.strptime() with datetime.fromisoformat() which correctly handles timezone information

Fixes #586

[sonarqubecloud]

Quality Gate passed

Issues
5 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 SonarQube Cloud

[KellianL]

Test are running using Python version 3.10.
The method used here to handle timestamp (timedate.fromisoformat) is available since Python 3.8 but only support most ISO 8601 formats since Python 3.11.