Remove TSCI section from Webcompat Metrics

[softvision-oana-arbuzov]

Tested with:
Browser / Version: Firefox Nightly 88.0a1 (2021-03-16), Chrome 89.0.4389.82
Operating System: Windows 10 Pro

Steps to reproduce:

1. Navigate to http://webcompat-dashboard.herokuapp.com/tsci?
2. Observe the page.

Expected Behavior:
TSCI section is not available (hidden).

Actual Behavior:
An error page is displayed.

Notes:

1. Screenshot attached.
   
2. Last update on the "Top-500 Site Compatibility Index" document was performed on 2019/8/18.

Watchers:
@softvision-oana-arbuzov
@softvision-raul-bucata

[magsout]

@karlcow

[karlcow]

@magsout yes we can remove it. We are not collecting the data anymore.

[magsout]

@karlcow oh ok, I'll opened a pr on metrics client to remove it.