build(deps): bump pitest-maven from 1.6.3 to 1.6.4 in /lambda

Bumps [pitest-maven](https://github.com/hcoles/pitest) from 1.6.3 to 1.6.4.
- [Release notes](https://github.com/hcoles/pitest/releases)
- [Commits](hcoles/pitest@1.6.3...1.6.4)

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

lambda/pom.xml

@@ -46,7 +46,7 @@
     <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>
-    <pitest-maven.version>1.6.3</pitest-maven.version>
+    <pitest-maven.version>1.6.4</pitest-maven.version>
     <pitest-junit5-plugin.version>0.12</pitest-junit5-plugin.version>
   </properties>