nghttp2 v1.56.0

What's Changed

• doc: Bump boringssl by @tatsuhiro-t in #1928
• Fix memory leak by @tatsuhiro-t in #1930
• Return void by @tatsuhiro-t in #1931
• nghttpx: Rework sending and receiving ECN bits by @tatsuhiro-t in #1934
• CMSG_DATA does not necessarily return an aligned pointer by @tatsuhiro-t in #1935
• Bump quictls by @tatsuhiro-t in #1937
• Bump ngtcp2 and its dependencies by @tatsuhiro-t in #1939
• nghttpx: Simplify std::unique_ptr get and release by @tatsuhiro-t in #1940
• Bump llhttp to 926c982942eb53a13f01c1e9e6b19bd3b196e7dd by @tatsuhiro-t in #1941
• Bump libbpf to v1.2.2 by @tatsuhiro-t in #1942
• Update Dockerfile by @tatsuhiro-t in #1943

Full Changelog: v1.55.0...v1.56.0