Exclude dependencies from Gradle file

Question

I have a dependency which exist in two places - one is in GitHub and another one is in internal Maven repository. While doing internal testing, I do testing from the Maven internal repository, and when doing release testing, I should get artifact only from GitHub and exclude the artifact downloading from internal Maven repository. I don't want to comment the Maven internal repository while doing release testing. How can I exclude a dependency downloading from the internal Maven repository.

allprojects {
    repositories {

        maven {
            url "https://github.com.sample.repo.url"

            credentials(HttpHeaderCredentials) {
                name = "Authorization"
                value = "Bearer " + "${findProperty('githubtoken')}"
            }
            authentication {
                header(HttpHeaderAuthentication)
            }
        }
        mavenCentral()
        maven {
            url "https://anotherurl.com"
            credentials {
                username "VSTS"
                password System.getenv("VSTS_ENV_ACCESS_TOKEN") ?: "${findProperty('vstsGradleAccessToken')}"
            }
            content {
                exclude group: 'somegroupname', module: 'somemodulename'
            }
        }
        
    }
}