Bump com.pi4j:pi4j-core from 1.4 to 2.6.0

Bumps [com.pi4j:pi4j-core](https://github.com/Pi4J/pi4j-v2) from 1.4 to 2.6.0.
- [Release notes](https://github.com/Pi4J/pi4j-v2/releases)
- [Changelog](https://github.com/Pi4J/pi4j-v2/blob/develop/autoRelease)
- [Commits](https://github.com/Pi4J/pi4j-v2/commits/2.6.0)

---
updated-dependencies:
- dependency-name: com.pi4j:pi4j-core
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

raspberrypi-boot-bmp085/pom.xml

@@ -57,7 +57,7 @@
         <dependency>
             <groupId>com.pi4j</groupId>
             <artifactId>pi4j-core</artifactId>
-            <version>1.4</version>
+            <version>2.6.0</version>
         </dependency>
 
         <!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind -->