And also require HTTP. Also add `IPv6` to the keywords.
Fixing:
Linux AM openssl !ipv6 !--libcurl:
```
FAIL 1265: 'NO_PROXY with IPv6 numerical address' HTTP, HTTP proxy, http_proxy, NO_PROXY, noproxy
FAIL 1324: 'HTTP with --resolve and [ipv6address]' HTTP, HTTP GET, --resolve
FAIL 2086: 'Pre-request callback for HTTP IPv6' HTTP, IPv6
```
Ref: https://github.com/curl/curl/actions/runs/14378524385/job/40318328714?pr=17012#step:41:3789
Follow-up to a09e49168a#17005Closes#17014
Unify the case, punctuation and name of test case keywords so they can
be more easily selected or skipped when desired. Add a few keywords that
were missing. Fix a couple of typos in test names.
missing CRs and modified %hostip
lib556/test556: use a real HTTP version to make test reuse more convenient
make sure the weekday in Date headers matches the date
test61: replace stray "^M" (5e 4d) at the end of a cookie with a '^M' (0d)
Gets the test working with external proxies like Privoxy again.
Closes#6463
