fix(excmd): :trust executed even when inside false condition (#36032)

Problem:  :trust is executed even when inside false condition.
Solution: Make skip_cmd() return true for CMD_trust, as ex_trust() does
          not handle eap->skip itself.

src/nvim/ex_docmd.c

@@ -1951,7 +1951,6 @@ static bool skip_cmd(const exarg_T *eap)
     case CMD_throw:
     case CMD_tilde:
     case CMD_topleft:
-    case CMD_trust:
     case CMD_unlet:
     case CMD_unlockvar:
     case CMD_verbose: