Fix typo in nori docs and tests (#92336)

C샤프 in English is C#, not C++.
(C++ in Korean is C플플, C쁠쁠 or C플러스플러스.)

The translation doesn't make sense, so I changed C++ to C#.
It might be true that the writer used C샤프 as just an independent example, regardless C++, but I think it is better to align them for better understanding.

docs/plugins/analysis-nori.asciidoc

@@ -82,7 +82,7 @@ dictionary to `$ES_HOME/config/userdict_ko.txt`:
 [source,txt]
 -----------------------
 c++                 <1>
-C샤프
+C쁠쁠
 세종
 세종시 세종 시        <2>
 -----------------------
@@ -176,7 +176,7 @@ PUT nori_sample
           "nori_user_dict": {
             "type": "nori_tokenizer",
             "decompound_mode": "mixed",
-            "user_dictionary_rules": ["c++", "C샤프", "세종", "세종시 세종 시"]
+            "user_dictionary_rules": ["c++", "C쁠쁠", "세종", "세종시 세종 시"]
           }
         },
         "analyzer": {

docs/src/test/cluster/config/userdict_ko.txt

@@ -1,5 +1,5 @@
 # Additional nouns
 c++
-C샤프
+C쁠쁠
 세종
-세종시 세종 시
+세종시 세종 시

plugins/analysis-nori/src/test/java/org/elasticsearch/plugin/analysis/nori/NoriAnalysisTests.java

@@ -75,7 +75,7 @@ public class NoriAnalysisTests extends ESTokenStreamTestCase {
     public void testNoriAnalyzerUserDict() throws Exception {
         Settings settings = Settings.builder()
             .put("index.analysis.analyzer.my_analyzer.type", "nori")
-            .putList("index.analysis.analyzer.my_analyzer.user_dictionary_rules", "c++", "C샤프", "세종", "세종시 세종 시")
+            .putList("index.analysis.analyzer.my_analyzer.user_dictionary_rules", "c++", "C쁠쁠", "세종", "세종시 세종 시")
             .build();
         TestAnalysis analysis = createTestAnalysis(settings);
         Analyzer analyzer = analysis.indexAnalyzers.get("my_analyzer");
@@ -108,7 +108,7 @@ public class NoriAnalysisTests extends ESTokenStreamTestCase {
         Settings settings = Settings.builder()
             .put("index.analysis.analyzer.my_analyzer.type", "nori")
             .put("index.analysis.analyzer.my_analyzer.user_dictionary", "user_dict.txt")
-            .putList("index.analysis.analyzer.my_analyzer.user_dictionary_rules", "c++", "C샤프", "세종", "세종시 세종 시")
+            .putList("index.analysis.analyzer.my_analyzer.user_dictionary_rules", "c++", "C쁠쁠", "세종", "세종시 세종 시")
             .build();
         IllegalArgumentException exc = expectThrows(IllegalArgumentException.class, () -> createTestAnalysis(settings));
         assertThat(

plugins/analysis-nori/src/test/resources/org/elasticsearch/plugin/analysis/nori/user_dict.txt

@@ -1,5 +1,5 @@
 # Additional nouns
 c++
-C샤프
+C쁠쁠
 세종
-세종시 세종 시
+세종시 세종 시