third_party: update libcurl from 8.3.0 to 8.4.0

The patch updates curl module to the version 8.4.0 [1] that brings a
number of functional fixes and security fix of SOCKS5 heap buffer
overflow (CVE-2023-38545), see description in [2] and commit
fb4415d8aee6 ("socks: return error if hostname too long for remote
resolve") in [3].

1. https://curl.se/changes.html#8_4_0
2. https://curl.se/docs/CVE-2023-38545.html
3. https://github.com/curl/curl/commit/fb4415d8aee6c1045be932a34fe6107c2f5ed147

NO_DOC=libcurl submodule bump
NO_TEST=libcurl submodule bump

(cherry picked from commit ee575fef)