Fix: Update slack channel link

[isabelle-dr]

Summary:

Update the link to our slack on our issue template page.
Previously a Google Form, now we have a direct link.
Expected behavior:

The link brings people directly to our slack instead of the google form

Please make sure these boxes are checked before submitting your pull request - thanks!

• [ ] Run the unit tests with gradle test to make sure you didn't break anything
• Format the title like "feat: [new feature short description]". Title must follow the Conventional Commit Specification(https://www.conventionalcommits.org/en/v1.0.0/).
• [ ] Linked all relevant issues
• [ ] Include screenshot(s) showing how this pull request works and fixes the issue(s)

[github-actions]

✅ Rule acceptance tests passed.
New Errors: 0 out of 1430 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
Dropped Errors: 0 out of 1430 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
New Warnings: 0 out of 1430 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
Dropped Warnings: 0 out of 1430 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
0 out of 1430 sources (~0 %) are corrupted.
Commit: 062557e
Download the full acceptance test report here (report will disappear after 90 days).
✅ Rule acceptance tests passed.

[emmambd]

LGTM!

[github-actions]

✅ Rule acceptance tests passed.
New Errors: 0 out of 1430 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
Dropped Errors: 0 out of 1430 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
New Warnings: 0 out of 1430 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
Dropped Warnings: 0 out of 1430 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
0 out of 1430 sources (~0 %) are corrupted.
Commit: 2016803
Download the full acceptance test report here (report will disappear after 90 days).
✅ Rule acceptance tests passed.