Remove slack link in Catalan translation #94531

[Rishidubey15]

Before submitting this pull request, check the changes to see it's only the changes you made intentionally
If there are changes to other lines you didn't make deliberately, it's possible that your IDE made the changes with a utility like prettier.
Next time, make sure that you only add your changes by using git add -p and rather than git add Contributors.md

If you're doing something in the checklist below, put an x inside [ ] so that - [ ] becomes - [x]

• I had fun going through this tutorial (ノ^o^)ノ and learned on the way ٩(＾◡＾)۶
• There are some things I'd like to improve in this tutorial. I have written them below.
• There were steps where I had errors while following this tutorial. I have written them below.

Include Tutorial to fix this:

1. Fork the repo.
2. Clone repo in your local machine. git clone .
3. cd first-contributions
4. Switch branch
5. Open README.ca.md the Catalan translation readme file.
6. Fix the broken slack link in line 111. And update with code-contributions URL(https://github.com/roshanjossey/code-contributions).
7. Stage the changes. git add .
8. Commit changes. git commit -m "Commit message like updated slack link"
9. Push to your remote repo. git push -u origin your-branch-name
10. Create a Pull Request(PR).

Fixes #94531