build(deps): bump flatten-maven-plugin from 1.2.2 to 1.2.7 (#37)

Bumps [flatten-maven-plugin](https://github.com/mojohaus/flatten-maven-plugin) from 1.2.2 to 1.2.7.
- [Release notes](https://github.com/mojohaus/flatten-maven-plugin/releases)
- [Commits](mojohaus/flatten-maven-plugin@1.2.2...flatten-maven-plugin-1.2.7)

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

pom.xml

@@ -49,7 +49,7 @@
     <maven-site-plugin.version>3.9.1</maven-site-plugin.version>
     <maven-source-plugin.version>3.2.1</maven-source-plugin.version>
     <maven-surefire-plugin.version>3.0.0-M5</maven-surefire-plugin.version>
-    <flatten-maven-plugin.version>1.2.2</flatten-maven-plugin.version>
+    <flatten-maven-plugin.version>1.2.7</flatten-maven-plugin.version>
     <jacoco-maven-plugin.version>0.8.6</jacoco-maven-plugin.version>
     <junit-platform-maven-plugin.version>1.1.2</junit-platform-maven-plugin.version>
     <license-maven-plugin.version>3.0</license-maven-plugin.version>