Update social media numbers

[reshamas]

code page:
https://github.com/pymc-devs/pymcon_web_series_website/blob/main/layouts/_default/sponsors.html

website page:
https://pymcon.com/sponsors/

• Update the social media reach numbers
• Update the date it was last updated

[reshamas]

@SangamSwadiK FYI, in case you would like to take this issue