feat: Enable backtrace for anyhow

[Xuanwo]

This PR enable backtrace feature for anyhow which helps a lot for debugging.

For example, after backtrace enabled, the output of error changed:

from

[2023-05-24T20:41:14Z ERROR sccache::server] ["openssl_sys"] fatal error: Not an archive file (invalid global header)

to

[2023-05-24T20:41:14Z ERROR sccache::server] ["openssl_sys"] fatal error: Not an archive file (invalid global header)
    
    Stack backtrace:
       0: <core::result::Result<T,F> as core::ops::try_trait::FromResidual<core::result::Result<core::convert::Infallible,E>>>::from_residual
                 at /rustc/84c898d65adf2f39a5a98507f1fe0ce10a2b8dbc/library/core/src/result.rs:2065:27
       1: sccache::util::hash_all_archives::{{closure}}::{{closure}}::{{closure}}
                 at /home/xuanwo/Code/mozilla/sccache/src/util.rs:153:29
       2: <tokio::runtime::blocking::task::BlockingTask<T> as core::future::future::Future>::poll

In which we know where this error come from.

[sylvestre]

could you please split your patch between the actual change and the reformat?

[codecov-commenter]

Codecov Report

Patch coverage has no change and project coverage change: -0.09 ⚠️

Comparison is base (1c6ec75) 29.37% compared to head (50a2beb) 29.28%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1774      +/-   ##
==========================================
- Coverage   29.37%   29.28%   -0.09%     
==========================================
  Files          49       49              
  Lines       17626    17626              
  Branches     8507     8506       -1     
==========================================
- Hits         5177     5162      -15     
+ Misses       7357     7338      -19     
- Partials     5092     5126      +34     

Impacted Files	Coverage Δ
src/lib.rs	5.58% <0.00%> (+0.16%)	⬆️

... and 12 files with indirect coverage changes

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[Xuanwo]

could you please split your patch between the actual change and the reformat?

DONE.