Code cleanup + .yml fix

[Ruthie-FRC]

This pull request introduces improvements to the build process and minor code corrections. The most significant update is the addition of Gradle caching to the GitHub Actions workflow, which will speed up CI builds. Other changes include a fix to the systemd service file for correct Java invocation and minor code cleanups in the main Java source.

Build process improvements:

• Added Gradle cache steps to the GitHub Actions workflow in .github/workflows/build.yml to cache dependencies and wrapper files, improving build times. [1] [2]

Deployment configuration:

• Fixed the ExecStart command in batteryTracking.service to use the -jar flag for running the Java application, ensuring the service starts correctly.

Code cleanup and bug fixes:

• Corrected a logic check in BatteryTracking.java to use != instead of !() == for clarity and correctness.
• Removed unnecessary semicolons and dead code in BatteryTracking.java for better code readability. [1] [2]

[Ruthie-FRC]

sorry abt earlier failed builds, its when I discovered the .yml issue