Excavator: Update open-source publishing plugins

Author: svc-excavator-bot

build.gradle

@@ -10,7 +10,7 @@ buildscript {
         classpath 'com.palantir.gradle.jdkslatest:gradle-jdks-latest:0.11.0'
         classpath 'com.palantir.gradle.consistentversions:gradle-consistent-versions:2.15.0'
         classpath 'com.palantir.gradle.gitversion:gradle-git-version:3.0.0'
-        classpath 'com.palantir.gradle.externalpublish:gradle-external-publish-plugin:1.17.0'
+        classpath 'com.palantir.gradle.externalpublish:gradle-external-publish-plugin:1.18.0'
         classpath 'com.palantir.javaformat:gradle-palantir-java-format:2.35.0'
         classpath 'gradle.plugin.org.inferred:gradle-processors:3.7.0'
         constraints {