Revert changing log level in FileUtils.kt (#2801)

Follow up on #2787

ktlint-cli/src/main/kotlin/com/pinterest/ktlint/cli/internal/FileUtils.kt

@@ -1,11 +1,6 @@
 package com.pinterest.ktlint.cli.internal
 
-import ch.qos.logback.classic.Level
-import ch.qos.logback.classic.Logger
 import com.pinterest.ktlint.logger.api.initKtLintKLogger
-import com.pinterest.ktlint.logger.api.setDefaultLoggerModifier
-import io.github.oshai.kotlinlogging.DelegatingKLogger
-import io.github.oshai.kotlinlogging.KLogger
 import io.github.oshai.kotlinlogging.KotlinLogging
 import org.jetbrains.kotlin.util.prefixIfNot
 import java.io.File
@@ -25,22 +20,7 @@ import kotlin.io.path.pathString
 import kotlin.io.path.relativeToOrSelf
 import kotlin.system.measureTimeMillis
 
-private val LOGGER =
-    KotlinLogging
-        .logger {}
-        .setDefaultLoggerModifier { it.level = Level.TRACE }
-        .initKtLintKLogger()
-
-private var KLogger.level: Level?
-    get() = underlyingLogger()?.level
-    set(value) {
-        underlyingLogger()?.level = value
-    }
-
-private fun KLogger.underlyingLogger(): Logger? =
-    @Suppress("UNCHECKED_CAST")
-    (this as? DelegatingKLogger<Logger>)
-        ?.underlyingLogger
+private val LOGGER = KotlinLogging.logger {}.initKtLintKLogger()
 
 private val ROOT_DIR_PATH: Path = Paths.get("").toAbsolutePath()