... even though they use the curl option "--resolve".
This makes it more convenient to choose or skip the tests.
For example Privoxy's cts test framework relies on the "--resolve"
keyword when executing the "upstream-tests" scenario to skip curl
tests that aren't expected to work when the requests are made through
Privoxy. While some of the modified tests are already skipped for
other reasons through other means when testing Privoxy, it's good to
be consistent.
Closes#21930
To formalize they are now XML-compliant (with some asterisks.)
Also to help syntax highlighters work on them to make their content more
readable.
Also:
- Delete empty comment decorations.
- GHA/checksrc: simplify XML check.
- runtests: fail to load test data with XML prolog missing.
Follow-up to bfe6eb1c06#19927
Follow-up to 87ba80a6dfCloses#19946
