Update Transformers version

[lbabetto]

Current transformers version (4.46.*) is affected by the following vulnerabilities:

• https://github.com/Eurocc-Italy/Vectoria/security/dependabot/1 (High severity)
• https://github.com/Eurocc-Italy/Vectoria/security/dependabot/2 (High severity)
• https://github.com/Eurocc-Italy/Vectoria/security/dependabot/3 (High severity)
• https://github.com/Eurocc-Italy/Vectoria/security/dependabot/4 (Moderate severity)
• https://github.com/Eurocc-Italy/Vectoria/security/dependabot/5 (Moderate severity)

The first 4 vulnerabilities were patched in version 4.48.0 while the last was patched in 4.50.0. If compatible with the workflow, let's consider updating the minimum required version accordingly.