feat: Create a workflow that label/unlabel issues on pin/unpin

[davorpa]

To enhace with #7053 stale labeling bypass, create a GitHub Actions workflow that automanage labels on pin/unpin issues.

When

• Pin an issue... add a label 📌 pinned
• Unpin an issue... remove the label 📌 pinned
• Optional: close a issue... remove the label 📌 pinned

[mohitsaxenaknoldus]

Hey, can I work on this?

[eshellman]

two heads are better than one