fix(triple): skip unsupported compat trailer attachments

[leno23]

What

• Skip old triple compat response attachments that cannot be represented as HTTP trailer values.
• Keep string and []string attachments unchanged.
• Add a regression test for bool attachment values.

Why

Issue #3093 reported that the old triple compat unary handler can panic when provider filters add internal attachments such as bool values. Those values should not fail the RPC response path just because they cannot be written as HTTP trailers.

Validation

• go test ./protocol/triple/triple_protocol
• go test ./protocol/triple/...
• git diff --check

Refs #3093

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 53.53%. Comparing base (60d1c2a) to head (a27918c).
⚠️ Report is 843 commits behind head on develop.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #3418      +/-   ##
===========================================
+ Coverage    46.76%   53.53%   +6.76%     
===========================================
  Files          295      493     +198     
  Lines        17172    38379   +21207     
===========================================
+ Hits          8031    20547   +12516     
- Misses        8287    16179    +7892     
- Partials       854     1653     +799     

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[Alanxtl]

@NeverENG @CAICAIIs help review this

[CAICAIIs]

Code path looks good to me.
and pr body can change Fixes part of #3093 to Refs #3093 and make sure it does not close the broader linked trackers.