Update rust according to moz-central updates [ci full]

[skhamis]

fixes #4485,

According to our Rust policy we should be updating our toolchain to keep up with moz-central.

Note: Most of the changes came from running cargo clippy --fix and some hand-changed but almost all of them are dealing the error:

error: this expression borrows a reference that is immediately dereferenced by the compiler

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  • Note:
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• Tests: This PR includes thorough tests or an explanation of why it does not
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[mhammond]

looks good to me in general, but flagging some nimbus folk

[codecov-commenter]

Codecov Report

Merging #4486 (935555b) into main (e178659) will decrease coverage by 0.01%.
The diff coverage is 54.54%.

@@            Coverage Diff             @@
##             main    #4486      +/-   ##
==========================================
- Coverage   75.31%   75.30%   -0.02%     
==========================================
  Files          47       47              
  Lines        4262     4260       -2     
==========================================
- Hits         3210     3208       -2     
  Misses       1052     1052              

Impacted Files	Coverage Δ
components/nimbus/examples/experiment.rs	0.00% <0.00%> (ø)
components/support/viaduct-reqwest/src/lib.rs	59.32% <0.00%> (ø)
components/viaduct/src/headers.rs	54.38% <ø> (ø)
components/nimbus/src/lib.rs	64.89% <15.00%> (ø)
components/nimbus/src/dbcache.rs	70.00% <100.00%> (ø)
components/nimbus/src/enrollment.rs	95.69% <100.00%> (-0.01%)	⬇️
components/nimbus/src/evaluator.rs	97.68% <100.00%> (ø)
components/nimbus/src/persistence.rs	94.20% <100.00%> (ø)
components/support/guid/src/lib.rs	87.14% <100.00%> (ø)

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[skhamis]

Given that there is quite a few (mechanical) changes. @jhugman, @travis79 -- this is where the main rust version bump actually comes from

[travis79]

That's a lot of borrows being returned! I don't have any objection or concerns that can see, carry on!