The TVTropes Trope Finder is where you can come to ask questions like "Do we have this one?" and "What's the trope about...?" Trying to rediscover a long lost show or other medium but need a little help? Head to Media Finder and try your luck there. Want to propose a new trope? You should be over at You Know, That Thing Where.
Not really, because in movies it's accepted that an actor doesn't have the skills of his character.
For example: Al is a brilliant and handsome software designer goes around with his cripplingly shy assistant Bob. It turns out Bob is the software genius, but he hired Al (who understands enough about software to give a good presentation) to present his works for him, and is okay with Al taking the credit if it gets Bob's works out in the business world.
Bob is the Hypercompetent Sidekick
We can never truly eradicate the coronavirus, but we can suppress its threat like influenza
Inverted Chessmaster Sidekick, with a touch of played-with Playing Cyrano?
Talent Double is about someone standing in for an actor to show a skill the character has but the actor doesn't. What's the trope for it happening for real (as in, the character lacks the talent he supposedly possesses and fakes by using another character who can do it). Sometimes it's a partnership (Alice has the talent but has No Social Skills, Bob is good with people but can't do what Alice does, so they pretend Bob has the skill and Alice is his assistant), sometimes the faker is forcing the talent to make him look good.
In Discworld/Maskerade, the star of the show is Christine, who certainly looks the part of a ballet heroine but is painfully unmusical. Agnes Nitt's Magic Music lets her sing the part of Christine while part of the chorus.