docs: fix broken external and internal links in Groovydocs#15327

sanjana2505006 wants to merge 1 commit intoapache:7.0.xapache/grails-core:7.0.xfrom

sanjana2505006:fix/groovydoc-linkssanjana2505006/grails-core:fix/groovydoc-linksCopy head branch name to clipboard