That would require you to edit the jazz script associated with the computer and remove that particular animation. The game’s jazz scripts are located in Program Files -> The Sims 3 -> Game -> Bin -> Jazz.
1. Open the JazzData package file with s3pe, find the appropriate jazz script, and export it to a package file.
2. Open the jazz script with SmoothJazz and remove the unwanted animation (the animation names are pretty self explanatory).
3. Save it as a new package.
4. Open up
S3PE and create a new package.
5. Import your edited jazz script, then save the package.
6. Place the new package in your Mods/Packages folder.
7. Test in game.
7a. If the unwanted animation still plays, move the package to your Overrides folder.
8. Profit!