Upgrade jgit from the jOOQ-migrations prototype to 6.6.1.202309021850-r

[lukaseder]

Dependabot suggested this upgrade here:
#15610

We've already merged it in jOOQ 3.19.0, but this might be worth including also in patch releases as:

• The jOOQ-migrations module is a prototype that no one (?) uses in production (I hope?)
• The vulnerability CVE-2023-4759 (which is rated 8.8 even if in jOOQ's case, it might as well be rated 1.0, as always) hurt jOOQ's ranking in these braindead automated reports

[lukaseder]

Fixed in versions

• 3.19.0
• 3.18.8 (Upgrade jgit from the jOOQ-migrations prototype to 6.6.1.202309021850-r - Merge [#15697] #15698)
• 3.17.17 (Upgrade jgit from the jOOQ-migrations prototype to 6.6.1.202309021850-r - Merge [#15697] #15699)
• 3.16.23 (Upgrade jgit from the jOOQ-migrations prototype to 6.6.1.202309021850-r - Merge [#15697] #15700)

[lukaseder]

The reason why I didn't backport this upgrade was because jgit 6 seems to require Java 11 now, and I wouldn't want to remove support for the module (even if experimental) in a patch release.