Fix ExecuteCallbackWithCtx to use the context that was provided

[doug-threatmate]

This updates ExecuteCallbackWithCtx to use the context that was provided.

Proposed changes

Recently, context support was added in various places in Nuclei. In particular, ExecuteCallbackWithCtx was added to replace ExecuteCallback. However, the context that is passed in to ExecuteCallbackWithCtx is unused.

This change passes that context along to ExecuteScanWithOpts instead of using context.Background().

Checklist

• Pull request is created against the dev branch
• All checks passed (lint, unit/integration/regression tests etc.) with my changes
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

[stan-threatmate]

@tarunKoyalwar this is needed to allow for context cancellation through the SDK.

[GeorginaReeder]

Thanks so much for your contribution @doug-threatmate , we appreciate it!

[tarunKoyalwar]

thanks for PR and looks like i missed this , after taking a closer look , it seems like there are more hardcoded context especially when creating new RateLimiter in library, i fixed this in this branch but i am getting 403 when i push changes

@doug-threatmate @stan-threatmate , can you give push access to this PR/branch https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/working-with-forks/allowing-changes-to-a-pull-request-branch-created-from-a-fork

[doug-threatmate]

@tarunKoyalwar I don't have the button that your guide references, but I did invite you to the repo, so maybe that'll do the same thing.

[tarunKoyalwar]

lgtm !

sorry about the delay , but i have removed all hardcoded contexts in library, this required a change in two public facing functions

NewThreadSafeNucleiEngine(opts ..)
NewNucleiEngine(opts ...)

both of them are now marked as deprecated in favour of

NewThreadSafeNucleiEngineCtx(ctx context.Context,opts ..)
NewNucleiEngineCtx(ctx context.Context, opts ...)

the earlier ones will still work but using those functions is not recommended because if context is cancelled it might cause goroutine leaks