Ruby: drop unused predicates that do not exist in Python variant

Author: aibaars

ruby/ql/lib/codeql/ruby/regexp/RegExpTreeView.qll

@@ -750,10 +750,6 @@ class RegExpGroup extends RegExpTerm, TRegExpGroup {
   /** Gets the name of this capture group, if any. */
   string getName() { result = re.getGroupName(start, end) }
 
-  predicate isCharacter() { any() }
-
-  string getValue() { result = re.getText().substring(start, end) }
-
   override RegExpTerm getChild(int i) {
     result.getRegExp() = re and
     i = 0 and
@@ -852,8 +848,6 @@ class RegExpCaret extends RegExpSpecialChar {
 class RegExpZeroWidthMatch extends RegExpGroup {
   RegExpZeroWidthMatch() { re.zeroWidthMatch(start, end) }
 
-  override predicate isCharacter() { any() }
-
   override RegExpTerm getChild(int i) { none() }
 
   override string getAPrimaryQlClass() { result = "RegExpZeroWidthMatch" }