How to resolve a conflict with a system scope dependency jar - maven

Question

I have a jar that my code depends on and it is located locally on my PC.
That jar contains the 'org.apache.commons.lang3' package but an older version or a version that contains the class 'StringUtils' but without all of its methods.
In my maven pom, I am using the 'org.apache.commons.lang3' dependency also but at runtime I get the error 'NoSuchMethodError' which means that during runtime it is using the commons.lang3 version of the jar and not the one from my dependency.
Is there a way to force it to use the dependency in my pom file?
Here is how my pom looks like:
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>test</groupId>
<artifactId>test</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.target>1.8</maven.compiler.target>
<maven.compiler.source>1.8</maven.compiler.source>
<test.path>C:/Users/user/test</test.path>
</properties>
<dependencies>
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
<version>3.12.0</version>
</dependency>
<dependency>
<groupId>dep</groupId>
<artifactId>dep</artifactId>
<version>1.0</version>
<scope>system</scope>
<systemPath>${test.path}/dep.jar</systemPath>
</dependency>
</dependencies>
<!-- build fat jar file with dependencies -->
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-shade-plugin</artifactId>
<version>3.2.1</version>
<configuration>
<shadedArtifactAttached>true</shadedArtifactAttached>
<shadedClassifierName>dep-included</shadedClassifierName>
<outputDirectory>${test.path}/out</outputDirectory>
</configuration>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>shade</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
</project>
CONCLUSION FROM COMMENTS:
It is not possible to remove such packages in a jar with Maven. I have to manualy edit and remove the packages from the jar file.
Thank you all for taking the time to answer!