fix(learn) : update the quiz cert footer

[a2937]

Checklist:

• I have read and followed the contribution guidelines.
• I have read and followed the how to open a pull request guide.
• My pull request targets the main branch of freeCodeCamp.
• I have tested these changes either locally on my machine, or GitPod.

Closes #54282

The wording for the description of the certification has been updated and the footer is now conditionally not present for the C# exam certification.

[naomi-lgbt]

Not sure what a handing is, but probably not something either of us want.

[a2937]

Typo has been fixed.

[Sembauke]

Hey @a2937,

Thank you for making this pr. Some of the test are failing could you take a look?

If you need any help with resolving the test errors let me know!

[a2937]

I don't understand why the tests are failing on GitHub. While I did modify my local development user account to gain this certificate (plus did a quick change back and forth on the tests) nothing seemed broken. The only reason why the tests failed locally were because the issuing dates were different the seed data results.

[naomi-lgbt]

I had weirdness with toBeNull().