Migrate to SCTP options API

[JoTurk]

Description

Migrate to SCTP options API.

[Copilot]

Pull request overview

This PR migrates SCTP association creation from the sctp.Config struct API to the newer ClientWithOptions functional options API, updating dependency versions accordingly.

Changes:

• Replace sctp.Client(sctp.Config{...}) usage with sctp.ClientWithOptions(...) in SCTPTransport.Start.
• Introduce helper methods to build the SCTP client options list, including conditional (optional) options.
• Add a unit test to ensure optional SCTP options are included when enabled, and bump github.com/pion/sctp to v1.9.3.

Reviewed changes

Copilot reviewed 3 out of 4 changed files in this pull request and generated 1 comment.

File	Description
sctptransport.go	Migrates SCTP client initialization to ClientWithOptions and centralizes option construction.
sctptransport_test.go	Adds coverage ensuring optional SCTP settings result in additional options being passed.
go.mod	Updates github.com/pion/sctp dependency to v1.9.3.
go.sum	Updates checksums corresponding to the SCTP dependency bump.

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 85.53%. Comparing base (87b7c3e) to head (b409f21).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3397      +/-   ##
==========================================
+ Coverage   85.51%   85.53%   +0.02%     
==========================================
  Files          81       81              
  Lines        9746     9761      +15     
==========================================
+ Hits         8334     8349      +15     
+ Misses        996      995       -1     
- Partials      416      417       +1     

Flag	Coverage Δ
go	85.53% <100.00%> (+0.02%)	⬆️

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