Tracking Primary key integer overflow risk for `web_hook_logs`
`web_hook_logs` is a large table with a lot of records. It's primary key is an integer-typed sequence with results in a maximum number of 2,147,483,647 records with a positive primary key in this table.
The current maximum id is 1.18B - or about 55.40% of the overall available space:
```
current_date | current_max | percentage_used
--------------+-------------+-----------------
2020-11-02 | 738106358 | 34.37
2021-02-22 | 1039948131 | 48.43
2021-03-19 | 1128918752 | 52.57
2021-04-10 | 1189728738 | 55.40
```
This issue is to track the state of this, provide estimates when the overflow is expected to happen and to discuss possible solutions to it.
According to our [forecast on 2021-02-22](https://gitlab.com/gitlab-org/gitlab/-/issues/320898#note_514276636) `web_hook_logs` Primary Key value is the fastest growing, expected to overflow between August 2021 (at a worst case scenario using an exponential forecast) and November 2021 (following a polynomial model).

### Solution
Partitioning: web_hook_logs table (&5558) - We will tackle the primary key migration and partitioning work at the same time. Details in the epic listed above.
issue