Add ability to disable or override tracer in pkg/op (private variable makes it impossible)

[valerijhegaj]

Preflight Checklist

• I could not find a solution in the existing issues, docs, nor discussions
• I have joined the ZITADEL chat

Describe your problem

Problem

Hello, we want to use this library in a large financial institution. Tracing is enabled too aggressively inside github.com/zitadel/oidc/v3/pkg/op, but unlike the pkg/client package, the tracer there is a private variable.
Because of this, we cannot override or disable tracing without using unsafe hacks (go:linkname), which is not acceptable for production in regulated environments.
Example:

• In github.com/zitadel/oidc/v3/pkg/client, the tracer is public and can be replaced.
• In github.com/zitadel/oidc/v3/pkg/op, the tracer is private, so there is no official way to disable or customize it.

Why this is a problem

Many companies (banks, enterprise, government) have strict policies about:
Disabling unnecessary tracing
Controlling telemetry centrally
Avoiding unsafe code and fork maintenance
Right now, the only way to disable tracing inside pkg/op is to patch it manually or use unsafe.

Describe your ideal solution

Suggested solution

Any of the following would solve the issue cleanly:

Option 1 (preferred)

Make the tracer exported:

var Tracer = ...

Option 2

Expose a function:

func SetTracer(trace.Tracer)

Option 3

Expose a function to configure or disable tracing:

func DisableTracing() 
// or
func ConfigureTracing(provider trace.TracerProvider)

Why this change is useful

Keeps API backward-compatible
Removes the need for unsafe or custom forks
Makes behavior consistent with pkg/client
Allows regulated environments to integrate safely

Version

v3.45.0

Environment

Self-hosted

Additional Context

No response