Add CI test run to libvlcsharp 4

[mfkl]

just checking the build

[mfkl]

some of the failing tests are libvlc 4 regressions. Ideally, we'd need a test for each libvlc callback.

[mfkl]

Need to have another look, this would be useful about now..

[koushikcs562]

’m interested in improving the libvlcsharp CI and test reliability. My approach would be to ensure that all tests run consistently in CI, handling regressions in libvlc 4 and disabling or adapting tests that fail due to environment-specific issues. This would involve adding targeted test tasks, fixing dead URLs, and making the CI run resilient while maintaining coverage for critical callbacks. This ensures that future contributions can be tested automatically and reliably.

[mfkl]

feel free to open a PR, but if you're looking for an easy first issue, this isn't it

[koushikcs562]

thanks for the guidance! I’ll come up with a PR shortly. I understand it might be a bit challenging, but I see this as a great learning opportunity to improve the libvlcsharp CI and test reliability. Looking forward to contributing and getting feedback!