MXTS-74974: buildMicroDocs/buildJavadoc classpath should use compileClasspath, not api

Both tasks set classpath = project.configurations.api. Git history shows
this used to be configurations.compile before the Gradle 5 migration
(commit 0a020fb), where it was mechanically swapped to `api` - the wrong
1:1 replacement. `api` is a narrow "exposed dependencies" bucket; the
correct modern equivalent of the old `compile` classpath is
compileClasspath, which is what the standard Gradle javadoc task uses
by default.

The bug this causes: any type referenced in project source but pulled in
via an `implementation`-scoped dependency is invisible to these tasks,
even though the main compileJava task (which uses compileClasspath)
compiles it fine. Surfaced by availability-service's ES 9.3.5 upgrade,
where co.elastic.clients.transport.rest5_client.Rest5ClientTransport
(from elasticsearch-java, implementation-scoped) failed to resolve while
Rest5Client/Rest5ClientBuilder (from elasticsearch-rest5-client,
api-scoped) resolved fine in the same file - consistent with this
exact classpath gap.

Verified: applying this fixed plugin (published to mavenLocal) to
availability-service with elasticsearch-java back on implementation
scope makes buildMicroDocs pass with no other changes.

Author: mxt-mischa

microdocs-crawler-gradle/build.gradle

@@ -61,7 +61,7 @@ dependencies {
 }
 
 group = 'com.maxxton'
-version = '4.0.0'
+version = '4.0.2'
 
 
 task fatJar(type: Jar, dependsOn: 'jar') {

microdocs-crawler-gradle/src/main/groovy/com/maxxton/microdocs/crawler/gradle/MicroDocsCrawlerPlugin.groovy

@@ -48,20 +48,18 @@ class MicroDocsCrawlerPlugin implements Plugin<Project> {
 
     project.task('buildMicroDocs', type: MicroDocs, dependsOn: ['extractMicroDocsDoclet'], group: 'microdocs') {
       title = ""
-      project.configurations.api.setCanBeResolved(true)
       source = project.sourceSets.main.allJava
-      classpath = project.configurations.api
+      classpath = project.sourceSets.main.compileClasspath
       destinationDir = project.reporting.file('./')
       options.docletpath = [new File("$project.buildDir/tmp/" + jarName)]
       options.doclet = 'com.maxxton.microdocs.crawler.doclet.DocletRunner'
     }
 
     project.task('buildJavadoc', type: Javadoc, group: 'microdocs') {
       title = ""
-      project.configurations.api.setCanBeResolved(true)
       source = project.sourceSets.main.allJava
       destinationDir = project.reporting.file("javadoc")
-      classpath = project.configurations.api
+      classpath = project.sourceSets.main.compileClasspath
       options.tags = ['response', 'example', 'ignoreDownstreamCheck']
     }