Update RELEASE_NOTES.md for 1.5.22 release

[Arkatufus]

1.5.22 June 4th 2024

Akka.NET v1.5.22 is a patch release for Akka.NET with a few bug fixes and logging improvement.

• Streams: Bump Reactive.Streams to 1.0.4
• Remote: Bump DotNetty.Handlers to 0.7.6
• Core: Resolve CVE-2018-8292 for Akka.Streams and Akka.Remote
• Core: Expose BusLogging EventStream as public API
• Remote: Add cross-platform support to the exception serializer

On Resolving CVE-2018-8292

In order to resolve this CVE, we had to update DotNetty.Handlers to the latest version and unfortunately, this comes with about 10% network throughput performance hit. We are looking into possible replacement for DotNetty to improve this performance lost in the future (see #7225 for updates).

Before

Num clients, Total [msg], Msgs/sec, Total [ms], Start Threads, End Threads  
         1,  200000,    125000,    1600.62,            46,              76  
         5, 1000000,    494072,    2024.04,            84,              95  
        10, 2000000,    713013,    2805.73,           103,             107  
        15, 3000000,    724463,    4141.38,           115,             115  
        20, 4000000,    714669,    5597.66,           123,             123  
        25, 5000000,    684932,    7300.37,           131,             107  
        30, 6000000,    694525,    8639.88,           115,              93  

After

Num clients, Total [msg], Msgs/sec, Total [ms], Start Threads, End Threads
         1,  200000,    123763,    1616.32,            46,              73
         5, 1000000,    386101,    2590.66,            81,              90
        10, 2000000,    662691,    3018.54,            98,             104
        15, 3000000,    666223,    4503.86,           112,             113
        20, 4000000,    669681,    5973.89,           121,             113
        25, 5000000,    669255,    7471.86,           121,             105
        30, 6000000,    669121,    8967.61,           113,              92

COMMITS	LOC+	LOC-	AUTHOR
6	167	188	Aaron Stannard
3	93	10	Gregorius Soedharmo

You can see the full set of changes for Akka.NET v1.5.22 here.