docs:update slack invite link

CONTRIBUTING.md

@@ -34,7 +34,7 @@ Note that our [code of conduct](https://github.com/newrelic/.github/blob/main/CO
 
 ## Slack
 
-We host a public Slack with a dedicated channel for contributors and maintainers of open source projects hosted by New Relic.  If you are contributing to this project, you're welcome to request access to the #oss-contributors channel in the newrelicusers.slack.com workspace.  To request access, see https://newrelicusers-signup.herokuapp.com/.
+We host a public Slack with a dedicated channel for contributors and maintainers of open source projects hosted by New Relic.  If you are contributing to this project, you're welcome to request access to the #oss-contributors channel in the newrelicusers.slack.com workspace.  To request access, please use this [link](https://join.slack.com/t/newrelicusers/shared_invite/zt-1ayj69rzm-~go~Eo1whIQGYnu3qi15ng).
 
 ## Testing
 ### Functional Testing
@@ -76,4 +76,4 @@ and provides a safeguard that your change won't be broken by future development.
 There are some rare cases where code changes do not result in changed
 functionality (e.g. a performance optimization) and new tests are not required.
 In general, including tests with your pull request dramatically increases the
-chances it will be accepted.
+chances it will be accepted.