build: bump to log4j-slf4j2-impl v2.25.0 (#1269)

Throughout this entire time, for anybody cloning the repository, setting
up the `config.json.template`, following all the steps from the GitHub
wiki we have verbatim and running the bot, leads to a SLF4J(E)
stacktrace into the console almost as soon as the program begins
execution, regardless of the environment:

    SLF4J(E): Unexpected problem occurred during version sanity check
    SLF4J(E): Reported exception:
    java.lang.AbstractMethodError: Receiver class org.apache.logging.slf4j.SLF4JServiceProvider does not define or inherit an implementation of the resolved method 'abstract java.lang.String getRequestedApiVersion()' of interface org.slf4j.spi.SLF4JServiceProvider.
	at org.slf4j.LoggerFactory.versionSanityCheck(LoggerFactory.java:385)
	at org.slf4j.LoggerFactory.performInitialization(LoggerFactory.java:189)
	at org.slf4j.LoggerFactory.getProvider(LoggerFactory.java:511)
	at org.slf4j.LoggerFactory.getILoggerFactory(LoggerFactory.java:497)
	at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:446)
	at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:472)
	at org.togetherjava.tjbot.Application.<clinit>(Application.java:35)

There has been no major hurdle noted after this exception being thrown,
at least not one that I am personally aware of.

Fix this by updating `log4j-slf4j2-impl` to the latest stable version as
of writing this (2.25.0). As a result, the stacktrace is entirely gone
and logging appears to be behaving normally.

By doing this we also prevent discouraging novice contributors from
contributing by falsely getting them to believe that they have performed
something wrong during setup.

Signed-off-by: Chris Sdogkos <work@chris-sdogkos.com>

Author: christolis

application/build.gradle

@@ -49,7 +49,7 @@ dependencies {
     implementation 'net.dv8tion:JDA:5.6.1'
 
     implementation 'org.apache.logging.log4j:log4j-core:2.25.0'
-    runtimeOnly 'org.apache.logging.log4j:log4j-slf4j18-impl:2.18.0'
+    runtimeOnly 'org.apache.logging.log4j:log4j-slf4j2-impl:2.25.0'
 
     implementation 'club.minnced:discord-webhooks:0.8.2'