ci(java): enable auto-publish for Java SDK with SNAPSHOT semantics

[hubcio]

SNAPSHOT versions are mutable -- republished on every build.
They bypass the tag gate (no tag created) and use a path
filter on foreign/java/ to skip unrelated pushes. Removing
SNAPSHOT from the version stops auto-publish automatically.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 69.51%. Comparing base (b53ef6d) to head (04cbc35).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #2696   +/-   ##
=======================================
  Coverage   69.50%   69.51%           
=======================================
  Files         568      568           
  Lines       55238    55238           
  Branches    55238    55238           
=======================================
+ Hits        38394    38398    +4     
+ Misses      14967    14961    -6     
- Partials     1877     1879    +2     

Flag	Coverage Δ
rust	69.51% <ø> (+<0.01%)	⬆️

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see 5 files with indirect coverage changes

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