`--max_total_time` to be deprecated

[Samuel Moelius]

--max_total_time provides an option to kill afl-fuzz after a time limit. However, it has some downsides:

1. --max_total_time is the only option of cargo afl fuzz handled by cargo-afl and not passed to afl-fuzz. Thus, it is a maintenance burden.

   For example, --max_total_time partially broke with the upgrade to Clap 4. It still works if passed as cargo afl fuzz's first argument, but not if other arguments appear first.

2. The functionality that --max_total_time provides is also provided by afl-fuzz's -V <seconds> option. Thus, --max_total_time is actually redundant.

For these reasons, I intend to remove --max_total_time with the next incompatible version change of afl.rs, unless there are strong objections.

Regarding point 1, it is unfortunate that --max_total_time does not work as it did before the upgrade to Clap 4. That is, it would be nice to offer users the original functionality prior to the option's removal. However, there is no easy way to fix this with Clap 4 currently (see clap-rs/clap#4468), and I am concerned that switching back to Clap 3 could introduce additional bugs. Users that require the original functionality of --max_total_time should please use afl.rs 0.12.8.

[Samuel Moelius]

Removed in 0.13.0