fix: in stats, Compare values AND keys to have a fully deterministic order

[iTrooz]

When using watch sccache -s, the order of "Successful distributed compiles" can change randomly if two keys have the same value
This PR fixes this

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 85.71429% with 1 line in your changes missing coverage. Please review.

Project coverage is 67.18%. Comparing base (7025295) to head (45423c9).

Files with missing lines	Patch %	Lines
src/server.rs	85.71%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2403      +/-   ##
==========================================
+ Coverage   67.06%   67.18%   +0.11%     
==========================================
  Files          64       64              
  Lines       34718    34723       +5     
==========================================
+ Hits        23285    23330      +45     
+ Misses      11433    11393      -40     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.