ci: correct username of Sonatype Nexus

Author: KengoTODA

.github/workflows/build.yml

@@ -38,7 +38,7 @@ jobs:
         env:
           SONAR_TOKEN: ${{ secrets.SONAR_TOKEN }}
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-          ORG_GRADLE_PROJECT_sonatypeUsername: ${{ secrets.USERNAME }}
+          ORG_GRADLE_PROJECT_sonatypeUsername: ${{ secrets.SONATYPE_USERNAME }}
           ORG_GRADLE_PROJECT_sonatypePassword: ${{ secrets.SONATYPE_PASSWORD }}
           ORG_GRADLE_PROJECT_signingKey: ${{ secrets.SIGNING_KEY }}
           ORG_GRADLE_PROJECT_signingPassword: ${{ secrets.SIGNING_PASSWORD }}