docs: update community call time

[pavanvishnusai]

What this PR does / why we need it:

Updates the Akri README community call time from 9:00 AM PT to 8:00 AM to 9:00 AM PT.

The linked Akri community meeting notes currently list the developer call as taking place from 8:00 AM to 9:00 AM, so this keeps the README consistent with the meeting page.

Special notes for your reviewer:

Docs-only README change. No code or behavior changes.

If applicable:

• this PR has an associated PR with documentation in akri-docs
• this PR contains unit tests
• added code adheres to standard Rust formatting (cargo fmt)
• code builds properly (cargo build)
• code is free of common mistakes (cargo clippy)
• all Akri tests succeed (cargo test)
• inline documentation builds (cargo doc)
• all commits pass the DCO bot check by being signed off – see the failing DCO check for instructions on how to retroactively sign commits

[gauravgahlot]

A small relevant correction while we are at it. Thank you, for your contribution. :)

[gauravgahlot]

While we are at it:

Suggested change

	You can reach the Akri community via the [#akri](https://kubernetes.slack.com/messages/akri) channel in [Kubernetes Slack](https://kubernetes.slack.com) or join our [community calls](https://hackmd.io/@akri/S1GKJidJd) on the first Tuesday of the month from 8:00 AM to 9:00 AM PT.
	You can reach the Akri community via the [#akri](https://kubernetes.slack.com/messages/akri) channel in [Kubernetes Slack](https://kubernetes.slack.com) and/or join our [community calls](https://hackmd.io/@akri/S1GKJidJd) on the first Tuesday of the month from 8:00 AM to 9:00 AM PT.