Upgrade to Linux 5.3

Originally created by @intrigeri on #17117 (Redmine)

5.3.2-1~exp1 is going to land is experimental in the next few days. I doubt it’ll be in sid in time for 4.0~rc1, but if we ship 4.0~rc1 with 5.2, we’ll have a very difficult decision to make regarding 4.0 final: taking the risk of upgrading to 5.3 vs. not getting the security fixes that come with 5.3.

One option, suggested by hefee, would be to ship 5.3 from experimental in 4.0~rc1: it’s a bit more risky for 4.0~rc1 but allows us to ship 5.3 in 4.0 final with a lower risk of regressions, which is good.

Feature Branch: feature/17117-linux-5.3+force-all-tests

Related issues

• Related to #17104 (closed)
• Related to #17124 (closed)
• Related to #17236 (closed)
• Blocks #17024 (closed)