[Pkg-rust-maintainers] Update `bat` and `fd-find` in Bullseye

[peter green]

> For bat, it requires updating too many dependencies which might break 
> other binaries.


Looking at the dependencies of the latest version of bat.

ansi_colours >=1.0.0, <2.0.0: satisfied
ansi_term >=0.12.1, <0.13.0: satisfied
console >=0.13.0, <0.14.0: needs update to 0.13
   deps:
     encode_unicode ^0.3: satisfied
     lazy_static ^1: satisfied
     libc ^0.2: satisfied
     terminal_size ^0.1.13: satisfied in unstable, but autopkgtest would need to be dealt with to get it into testing
     winapi ^0.3: satisfied
     regex ^1.3.1: satisfied
     unicode-width ^0.1: satisfied
     winapi-util ^0.1.3: satisfied
   rdeps (other than bat):
     rust-console-error-panic-hook: no rdeps
     rust-indicatif: rdep from rust-hyperfine
       rust-hyperfine: no rdeps
content_inspector >=0.2.4, <0.3.0: satisfied
encoding >=0.2.0, <0.3.0: satisfied
error-chain >=0.12.0, <0.13.0: satisfied
globset >=0.4.0, <0.5.0: satisfied
path_abs >=0.5.0, <0.6.0: not packaged
   std_prelude ^0.2.12: satisfied
   serde ^1.0: satisfied
   serde_derive ^1.0: satisfied
   stfu8 ^0.2: satisfied
semver >=0.11.0, <0.12.01: has a bunch of important rdeps.
serde >=1.0.0, <2.0.0: satisfied
serde_yaml >=0.8.0, <0.9.0: satisfied
syntect >=4.4.0, <5.0.0: needs update, bat seems to be the only reverse dependency
   bitflags ^1.0.4: satisfied
   lazycell ^1.0: satisfied
   lazy_static ^1.0: satisfied
   plist ^1: satisfied
   serde ^1.0: satisfied
   serde_derive ^1.0: satisfied
   serde_json ^1.0: satisfied
   walkdir ^2.0: satisified
   bincode ^1.0: satsified
   fancy-regex ^0.3.2: version in Debian is at 0.4, would need investigating whether the dependency can be relaxed or removed (it's listed as optional on crates.io, so in the worst case it could probablly be removed by disableing a feature).
   flate2 ^1.0: satisfied
   fnv ^1.0: satisfied
   onig ^6.0: satisfied
   regex-syntax ^0.6: satisfied
   yaml-rust ^0.4: satisified
unicode-width >=0.1.8, <0.2.0: satisfied
atty >=0.2.14, <0.3.0: satisfied
clap >=2.33.0, <3.0.0: satisfied
dirs >=3.0.0, <4.0.0: satisfied
git2 >=0.13.0, <0.14.0: satisfied
lazy_static >=1.4.0, <2.0.0: satisfied
shell-words >=1.0.0, <2.0.0: satisfied
wild >=2.0.0, <3.0.0: satisfied

So if someone (won't be me) wants to work on updating bat I would suggest the following.

1. package path_abs and get it into new ASAP.
2. package the new version of syntect, investigate and deal with the
    fancy-regex issue and upload to expermimental.
3. Investigate whether it is possible to patch the new version of bat to work
    with the existing version of semver. If it is patch it, if not work on packaging
    the new version of semver in experimental and upload a rust-semver-0.9 package
    to satisfy the rdeps on the existing version.
4. upload the new version of bat to experimental.
5. once everything is in place and confirmed good (builds succesfully on all
    architectures, passes autopkgtests) transfer stuff from experimental to unstable