Update libcurl

Engine/lib/curl/docs/DEPRECATE.md

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+# Items to be removed from future curl releases
+
+If any of these deprecated features is a cause for concern for you, please
+email the
+[curl-library mailing list](https://lists.haxx.se/listinfo/curl-library)
+as soon as possible and explain to us why this is a problem for you and
+how your use case cannot be satisfied properly using a workaround.
+
+## NSS
+
+We remove support for building curl with the NSS TLS library in August 2023.
+
+- There are very few users left who use curl+NSS
+- NSS has very few users outside of curl as well (primarily Firefox)
+- NSS is harder than ever to find documentation for
+- NSS was always "best" used with Red Hat Linux when they provided additional
+  features on top of the regular NSS that is not shipped by the vanilla library
+
+Starting in 7.82.0, building curl to use NSS configure requires the additional
+flag --with-nss-deprecated in an attempt to highlight these plans.
+
+## NPN
+
+We make selecting NPN a no-op starting in August 2022.
+
+**Next Protocol Negotiation** is a TLS extension that was created and used for
+agreeing to use the SPDY protocol (the precursor to HTTP/2) for HTTPS. In the
+early days of HTTP/2, before the spec was finalized and shipped, the protocol
+could be enabled using this extension with some servers.
+
+curl supports the NPN extension with some TLS backends since then, with a
+command line option `--npn` and in libcurl with `CURLOPT_SSL_ENABLE_NPN`.
+
+HTTP/2 proper is made to use the ALPN (Application-Layer Protocol Negotiation)
+extension and the NPN extension has no purposes anymore. The HTTP/2 spec was
+published in May 2015.
+
+Today, use of NPN in the wild should be extremely rare and most likely totally
+extinct. Chrome removed NPN support in Chrome 51, shipped in
+June 2016. Removed in Firefox 53, April 2017.
+
+## past removals
+
+ - Pipelining
+ - axTLS
+ - PolarSSL