feat: migrate to github.com/urfave/cli/v3

[nrwiersma]

Goal of this PR

This migrates the CLI to v3, moving this module to v3 as well, due to the breaking change.

How did I test it?

[Copilot]

Copilot reviewed 21 out of 22 changed files in this pull request and generated no comments.

Files not reviewed (1)

• go.mod: Language not supported

Comments suppressed due to low confidence (3)

trace.go:54

• The flag type for 'FlagTracingTags' has been changed from StringSliceFlag to StringMapFlag; please ensure that downstream code consuming this flag is updated to handle map values rather than slices.

&cli.StringMapFlag{

profile.go:102

• Consider validating that each entry in newTypes corresponds to a supported profiling type before conversion to pyroscope.ProfileType to avoid unintended behavior at runtime.

if newTypes := cmd.StringSlice(FlagProfilingTypes); len(newTypes) > 0 {

observe/observer.go:102

• Using context.WithoutCancel(ctx) for tracer shutdown bypasses any cancellation or timeout; please verify that this is the intended behavior for a graceful shutdown in all scenarios.

closeFns = append(closeFns, func() { _ = tracer.Shutdown(context.WithoutCancel(ctx)) })