Upgrade to Git Commit ID Plugin 2.1.15

Closes gh-6276

Author: wilkinsona

spring-boot-dependencies/pom.xml

@@ -2142,7 +2142,7 @@
 				<plugin>
 					<groupId>pl.project13.maven</groupId>
 					<artifactId>git-commit-id-plugin</artifactId>
-					<version>2.1.11</version>
+					<version>2.1.15</version>
 				</plugin>
 			</plugins>
 		</pluginManagement>