Stop using Bintray to publish to Maven Central

This commit reworks the CI pipeline to remove the use of Bintray for
publishing to Maven Central. In its place it adds a new
publishToCentral command to the release scripts. This command can be
used to publish a directory tree of artifacts to the Maven Central
gateway hosted by Sonatype.

Publishing consists of 4 steps:

1. Create the staging repository
2. Deploy artifacts to the repository
3. Close the repository
4. Release the repository

The command requires 3 arguments:

1. The type of release being performed
2. Location of a build info JSON file that describes the release
   that is to be deployed
3. Root of a directory structure, in Maven repository layout, that
   contains the artifacts to be deployed

Closes gh-25107

ci/images/releasescripts/pom.xml

@@ -19,6 +19,11 @@
 		<spring-javaformat.version>0.0.26</spring-javaformat.version>
 	</properties>
 	<dependencies>
+		<dependency>
+			<groupId>org.bouncycastle</groupId>
+			<artifactId>bcpg-jdk15to18</artifactId>
+			<version>1.68</version>
+		</dependency>
 		<dependency>
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-starter</artifactId>

ci/images/releasescripts/src/main/java/io/spring/concourse/releasescripts/artifactory/ArtifactoryService.java

@@ -17,14 +17,10 @@
 package io.spring.concourse.releasescripts.artifactory;
 
 import java.net.URI;
-import java.time.Duration;
-import java.util.Set;
 
 import io.spring.concourse.releasescripts.ReleaseInfo;
 import io.spring.concourse.releasescripts.artifactory.payload.BuildInfoResponse;
-import io.spring.concourse.releasescripts.artifactory.payload.DistributionRequest;
 import io.spring.concourse.releasescripts.artifactory.payload.PromotionRequest;
-import io.spring.concourse.releasescripts.bintray.BintrayService;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -53,17 +49,11 @@ public class ArtifactoryService {
 
 	private static final String BUILD_INFO_URL = ARTIFACTORY_URL + "/api/build/";
 
-	private static final String DISTRIBUTION_URL = ARTIFACTORY_URL + "/api/build/distribute/";
-
 	private static final String STAGING_REPO = "libs-staging-local";
 
 	private final RestTemplate restTemplate;
 
-	private final BintrayService bintrayService;
-
-	public ArtifactoryService(RestTemplateBuilder builder, ArtifactoryProperties artifactoryProperties,
-			BintrayService bintrayService) {
-		this.bintrayService = bintrayService;
+	public ArtifactoryService(RestTemplateBuilder builder, ArtifactoryProperties artifactoryProperties) {
 		String username = artifactoryProperties.getUsername();
 		String password = artifactoryProperties.getPassword();
 		if (StringUtils.hasLength(username)) {
@@ -116,37 +106,6 @@ private boolean isAlreadyPromoted(String buildName, String buildNumber, String t
 		}
 	}
 
-	/**
-	 * Deploy builds from Artifactory to Bintray.
-	 * @param sourceRepo the source repo in Artifactory.
-	 * @param releaseInfo the resease info
-	 * @param artifactDigests the artifact digests
-	 */
-	public void distribute(String sourceRepo, ReleaseInfo releaseInfo, Set<String> artifactDigests) {
-		logger.debug("Attempting distribute via Artifactory");
-		if (!this.bintrayService.isDistributionStarted(releaseInfo)) {
-			startDistribute(sourceRepo, releaseInfo);
-		}
-		if (!this.bintrayService.isDistributionComplete(releaseInfo, artifactDigests, Duration.ofMinutes(60))) {
-			throw new DistributionTimeoutException("Distribution timed out.");
-		}
-	}
-
-	private void startDistribute(String sourceRepo, ReleaseInfo releaseInfo) {
-		DistributionRequest request = new DistributionRequest(new String[] { sourceRepo });
-		RequestEntity<DistributionRequest> requestEntity = RequestEntity
-				.post(URI.create(DISTRIBUTION_URL + releaseInfo.getBuildName() + "/" + releaseInfo.getBuildNumber()))
-				.contentType(MediaType.APPLICATION_JSON).body(request);
-		try {
-			this.restTemplate.exchange(requestEntity, Object.class);
-			logger.debug("Distribute call completed");
-		}
-		catch (HttpClientErrorException ex) {
-			logger.info("Failed to distribute.");
-			throw ex;
-		}
-	}
-
 	private PromotionRequest getPromotionRequest(String targetRepo) {
 		return new PromotionRequest("staged", STAGING_REPO, targetRepo);
 	}