Remove all Google Calendar references from documentation (#395)

* Initial plan

* Remove all Google Calendar references from documentation

Co-authored-by: alexeygrigorev <875246+alexeygrigorev@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: alexeygrigorev <875246+alexeygrigorev@users.noreply.github.com>

Author: Copilot

README.md

@@ -28,7 +28,6 @@ MLOps (machine learning operations) is a must-know skill for many data professio
 ### 2025 Cohort
 - **Start Date**: May 5, 2025
 - **Register Here**: [Sign up](https://airtable.com/shrCb8y6eTbPKwSTL)
-- **Stay Updated**: Subscribe to our [Google Calendar](https://calendar.google.com/calendar/?cid=M3Jzbmg0ZDA2aHVsY2M1ZjcyNDJtODNyMTRAZ3JvdXAuY2FsZW5kYXIuZ29vZ2xlLmNvbQ) (Desktop only)
 
 ### Self-Paced Learning
 All course materials are freely available for independent study. Follow these steps:
@@ -129,7 +128,6 @@ Interested in supporting our community? Reach out to [alexey@datatalks.club](mai
 <a href="https://datatalks.club/slack.html">Join Slack Community</a> •
 <a href="https://us19.campaign-archive.com/home/?u=0d7822ab98152f5afc118c176&id=97178021aa">Newsletter</a> •
 <a href="http://lu.ma/dtc-events">Upcoming Events</a> •
-<a href="https://calendar.google.com/calendar/?cid=ZjhxaWRqbnEwamhzY3A4ODA5azFlZ2hzNjBAZ3JvdXAuY2FsZW5kYXIuZ29vZ2xlLmNvbQ">Google Calendar</a> •
 <a href="https://www.youtube.com/@DataTalksClub/featured">YouTube</a> •
 <a href="https://github.com/DataTalksClub">GitHub</a> •
 <a href="https://www.linkedin.com/company/datatalks-club/">LinkedIn</a> •

after-sign-up.md

@@ -12,7 +12,6 @@ To make sure you don't miss any announcements
 - [Tweet about the course!](https://ctt.ac/fH67W)
 - Subscribe to [DataTalks.Club's YouTube channel](https://www.youtube.com/c/DataTalksClub) and check 
   [the course playlist](https://www.youtube.com/playlist?list=PL3MmuxUbc_hIUISrluw_A7wDSmfOhErJK)
-- Subscribe to our [public Google Calendar](https://calendar.google.com/calendar/?cid=M3Jzbmg0ZDA2aHVsY2M1ZjcyNDJtODNyMTRAZ3JvdXAuY2FsZW5kYXIuZ29vZ2xlLmNvbQ) (it works from Desktop only)
 - Check our [Technical FAQ](https://docs.google.com/document/d/12TlBfhIiKtyBv8RnsoJR6F72bkPDGEvPOItJIxaEzE0/edit) if you have questions 
 
 See you in May!