[MINOR][CORE] Remove dead code across gluten-core

gluten-core/src/main/scala/org/apache/gluten/config/ConfigBuilder.scala

@@ -19,7 +19,6 @@ package org.apache.gluten.config
 import org.apache.spark.network.util.{ByteUnit, JavaUtils}
 
 import java.util.concurrent.TimeUnit
-import java.util.regex.Pattern
 
 object BackendType extends Enumeration {
   type BackendType = Value
@@ -141,8 +140,6 @@ private object ConfigHelpers {
     }
   }
 
-  private val TIME_STRING_PATTERN = Pattern.compile("(-?[0-9]+)([a-z]+)?")
-
   def timeFromString(str: String, unit: TimeUnit): Long = JavaUtils.timeStringAs(str, unit)
 
   def timeToString(v: Long, unit: TimeUnit): String = s"${TimeUnit.MILLISECONDS.convert(v, unit)}ms"

gluten-core/src/main/scala/org/apache/gluten/extension/columnar/transition/FloydWarshallGraph.scala

@@ -89,12 +89,10 @@ object FloydWarshallGraph {
   private object Builder {
     private class Impl[V <: AnyRef, E <: AnyRef]() extends Builder[V, E] {
       private val pathTable: mutable.Map[V, mutable.Map[V, Path[E]]] = mutable.Map()
-      private var graph: Option[FloydWarshallGraph[V, E]] = None
 
       override def addVertex(v: V): Builder[V, E] = {
         assert(!pathTable.contains(v), s"Vertex $v already exists in graph")
         pathTable.getOrElseUpdate(v, mutable.Map()).getOrElseUpdate(v, Path(Nil))
-        graph = None
         this
       }
 
@@ -104,7 +102,6 @@ object FloydWarshallGraph {
         assert(pathTable.contains(to), s"Vertex $to not exists in graph")
         assert(!hasPath(from, to), s"Path from $from to $to already exists in graph")
         pathTable(from) += to -> Path(Seq(edge))
-        graph = None
         this
       }
 

gluten-core/src/main/scala/org/apache/gluten/extension/columnar/transition/package.scala

@@ -33,11 +33,11 @@ package object transition {
   //
   // Extend this list in shim layer once Spark has more.
   def canPropagateConvention(plan: SparkPlan): Boolean = plan match {
-    case p: DebugExec => true
-    case p: UnionExec => true
-    case p: AQEShuffleReadExec => true
-    case p: InputAdapter => true
-    case p: WholeStageCodegenExec => true
+    case _: DebugExec => true
+    case _: UnionExec => true
+    case _: AQEShuffleReadExec => true
+    case _: InputAdapter => true
+    case _: WholeStageCodegenExec => true
     case _ => false
   }