ci: stopping running PR builds with 3.5.5/3.5.6 (apache#4103)

Author: andygrove

.github/workflows/pr_build_linux.yml

@@ -248,19 +248,9 @@ jobs:
             maven_opts: "-Pspark-3.4 -Pscala-2.12"
             scan_impl: "auto"
 
-          - name: "Spark 3.5.5, JDK 17, Scala 2.13"
+          - name: "Spark 3.5, JDK 17, Scala 2.13"
             java_version: "17"
-            maven_opts: "-Pspark-3.5 -Dspark.version=3.5.5 -Pscala-2.13"
-            scan_impl: "auto"
-
-          - name: "Spark 3.5.6, JDK 17, Scala 2.13"
-            java_version: "17"
-            maven_opts: "-Pspark-3.5 -Dspark.version=3.5.6 -Pscala-2.13"
-            scan_impl: "auto"
-
-          - name: "Spark 3.5, JDK 17, Scala 2.12"
-            java_version: "17"
-            maven_opts: "-Pspark-3.5 -Pscala-2.12"
+            maven_opts: "-Pspark-3.5 -Pscala-2.13"
             scan_impl: "native_iceberg_compat"
 
           - name: "Spark 4.0, JDK 17"