chore: upgrade time crate

[hugocaillard]

Description

• Upgrade time crate to 0.3
• Remove time crate from clarity and stacks-common (unused)
• It removes 17 (old) dependencies from Cargo.lock.

Breaking change: this PR, in its current form, updates the header date format to actually follow the rfc 7231 format.
If this change isn't wanted, I can also format the data back to the old version (and still keep the dependency upgrade)

Additional info (benefits, drawbacks, caveats)

Checklist

• Test coverage for new or modified code paths
• Changelog is updated
• Required documentation changes (e.g., docs/rpc/openapi.yaml and rpc-endpoints.md for v2 endpoints, event-dispatcher.md for new events)
• New clarity functions have corresponding PR in clarity-benchmarking repo
• New integration test(s) added to bitcoin-tests.yml

[codecov]

Codecov Report

Attention: Patch coverage is 53.84615% with 6 lines in your changes missing coverage. Please review.

Project coverage is 77.78%. Comparing base (c86013a) to head (5e10cfa).
Report is 7 commits behind head on develop.

Files with missing lines	Patch %	Lines
stackslib/src/net/http/tests.rs	14.28%	6 Missing ⚠️

❌ Your project status has failed because the head coverage (77.78%) is below the target coverage (80.00%). You can increase the head coverage or adjust the target coverage.

Additional details and impacted files

@@             Coverage Diff              @@
##           develop    #6271       +/-   ##
============================================
+ Coverage    56.46%   77.78%   +21.31%     
============================================
  Files          546      546               
  Lines       347228   347236        +8     
  Branches       323      323               
============================================
+ Hits        196059   270081    +74022     
+ Misses      151161    77147    -74014     
  Partials         8        8               

Files with missing lines	Coverage Δ
stacks-common/src/util/mod.rs	88.88% <ø> (+1.38%)	⬆️
stackslib/src/net/http/response.rs	82.25% <100.00%> (+11.59%)	⬆️
stackslib/src/net/http/tests.rs	80.46% <14.28%> (+51.11%)	⬆️

... and 387 files with indirect coverage changes

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