[Feature] disable gz compression for json format in IT/E2E cases and fix checkstyle CI

Doris 2.1 does not support json compression, so disable default gz
compression for json format test cases. Also fix checkstyle CI to
install dependencies before running checkstyle:check.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: JNSimba

.github/workflows/checkstyle.yaml

@@ -40,7 +40,7 @@ jobs:
 
       - name: Run java checkstyle
         run:
-          cd flink-doris-connector && mvn clean checkstyle:check -Pflink1 -pl flink-doris-connector-flink1 -am
+          cd flink-doris-connector && mvn clean install checkstyle:check -DskipTests -Pflink1 -pl flink-doris-connector-flink1 -am
 
       - name: Setup java 17
         uses: actions/setup-java@v2
@@ -50,4 +50,4 @@ jobs:
 
       - name: Run java checkstyle
         run:
-          cd flink-doris-connector && mvn clean checkstyle:check -Pflink2 -pl flink-doris-connector-flink2 -am
+          cd flink-doris-connector && mvn clean install checkstyle:check -DskipTests -Pflink2 -pl flink-doris-connector-flink2 -am

flink-doris-connector/flink-doris-connector-flink1/src/test/java/org/apache/doris/flink/container/AbstractE2EService.java

@@ -142,6 +142,9 @@ protected void setSinkConfDefaultConfig(List<String> argList) {
         argList.add(JDBC_URL + "=" + getDorisQueryUrl());
         argList.add(SINK_CONF);
         argList.add(SINK_LABEL_PREFIX + "=" + "label");
+        // disable gz compression for json format, doris 2.1 does not support json compression
+        argList.add(SINK_CONF);
+        argList.add("sink.properties.compress_type=");
     }
 
     public static void closeE2EContainers() {