Fix slack link

* default slack.paketo.io is no longer working, probably since the slack account was transferred back to CloudFoundry Foundation
* use the invite link everywhere, it's valid

README.md

@@ -80,7 +80,7 @@ dictionary is usually preferred.
       staging URL.
 * Join website-related conversations in the
   [#website](https://paketobuildpacks.slack.com/archives/C0229DVMFM5) channel
-  of the [Paketo slack instance](https://slack.paketo.io/).
+  of the [Paketo slack instance](https://join.slack.com/t/paketobuildpacks/shared_invite/zt-2jayv12ro-eTP8AtcmvyIpEtlANfIb~g).
 
 ## Deployment
 This repo uses a GHA workflow to automatically deploy commits on `main` to the

layouts/community/list.html

@@ -20,7 +20,7 @@ <h3>There are a few good ways to keep up with developments within the Paketo Bui
 </section>
 <section class="homepage-section homepage-section--dark community-action-section">
 <div class="community-action-container">
-<a class="action-button" href="https://slack.paketo.io/">
+<a class="action-button" href="https://join.slack.com/t/paketobuildpacks/shared_invite/zt-2jayv12ro-eTP8AtcmvyIpEtlANfIb~g">
 <div class="action-button__content">
 <div class="action-button__image-container">
 <div class="logo">