Update the version in examples/maven/pom.xml after the release (#1440)

### What's done:

 * Now, after each release, the example Maven project version is correctly
   updated to match the next SNAPSHOT version.

.github/workflows/release.yml

@@ -85,6 +85,12 @@ jobs:
             cp diktat-rules/src/main/resources/diktat-analysis.yml $(dirname $file)
           done
           next_snapshot_version=$(printf 'VERSION=${project.version}\n0\n' | mvn help:evaluate | grep '^VERSION' | cut -d= -f2)
+          # Update the version in `examples/maven/pom.xml`
+          # (which is not a part of the multi-module project).
+          for file in examples/maven/pom.xml
+          do
+            sed -i "s|\(<version>\)[[:digit:]]\(\.[[:digit:]]\)\+-SNAPSHOT\(</version>\)|\1${next_snapshot_version}\3|g" "${file}" || echo "File ${file} hasn't been updated (2nd sed pass)"
+          done
           echo "version=$next_snapshot_version" > info/buildSrc/gradle.properties
       - name: Create pull request
         uses: peter-evans/create-pull-request@v4

examples/maven/pom.xml

@@ -5,7 +5,7 @@
     <groupId>org.cqfn.diktat</groupId>
     <artifactId>diktat-examples-maven</artifactId>
     <packaging>pom</packaging>
-    <version>1.2.1-SNAPSHOT</version>
+    <version>1.2.2-SNAPSHOT</version>
 
     <properties>
         <diktat.version>1.2.1</diktat.version>