multicursor: `f` only cascades if it succeeds on the primary cursor

Problem

In follow mode, fa tries to jump each cursor to the next instance a. And if the main cursor has an a after it, then it works, and all cursors with an a after them jump. But if the primary cursor doesn't have an a after it, then the motion doesn't cascade, and the other cursors don't attempt to jump.

This regressed in d24cafc06a78f6357674c2429706303538be48da (bisected).

Steps to reproduce

nvim --clean
:= vim.api.nvim_buf_set_lines(0, 0, -1, false, { " a", "  b", "   a", "    b" })
vGQ
fb
# observe that two cursors jump - second one and last one
0
fa
# observe that no cursors jump, even though the first and third one should

Expected behavior

The motion would cascade, even if it didn't "succeed" on the primary cursor - since it may succeed on others. I think f shouldn't "beep", or at least its beep should be ignored. The same of course goes for F / t / T.

System info

• Nvim version (nvim -v): nightly commit d24cafc06a78f6357674c2429706303538be48da
• Vim (not Nvim) behaves the same: no, no multicursor
• Operating system/version: NixOS unstable
• Terminal name/version: Kitty 0.48.2
• $TERM environment variable: xterm-kitty
• Installation: nixpkgs