fix: Fixed some compiler warnings (#5028)

* fix(C4101): unreferenced local variable

* fix(C4189): variable initialized but not referenced

* fix(C4305): narrowing from double to float

* fix(C4457): declaration hiding function parameter

* fix(C4456): shadowing declaration

* fix(C4996): remove deprecations

* chore: add changelog entry

* fix: Remove more unused variables

* fix: removed unused lambda captures

* Update changelog entry

---------

Co-authored-by: Rasmus Karlsson <rasmus.karlsson@pajlada.com>

src/providers/irc/AbstractIrcServer.cpp

@@ -11,10 +11,6 @@
 
 namespace chatterino {
 
-const int RECONNECT_BASE_INTERVAL = 2000;
-// 60 falloff counter means it will try to reconnect at most every 60*2 seconds
-const int MAX_FALLOFF_COUNTER = 60;
-
 // Ratelimits for joinBucket_
 const int JOIN_RATELIMIT_BUDGET = 18;
 const int JOIN_RATELIMIT_COOLDOWN = 12500;

src/providers/irc/IrcConnection2.cpp

@@ -16,7 +16,7 @@ IrcConnection::IrcConnection(QObject *parent)
 {
     // Log connection errors for ease-of-debugging
     QObject::connect(this, &Communi::IrcConnection::socketError, this,
-                     [this](QAbstractSocket::SocketError error) {
+                     [](QAbstractSocket::SocketError error) {
                          qCDebug(chatterinoIrc) << "Connection error:" << error;
                      });