Switched using classloader to using classgraph library.

It's past time to start deploying SciJava components
like this one to Maven Central!

Maven no longer supports plain HTTP for the schema location.

And using HTTP now generates errors in Eclipse (and probably other IDEs).

Signed-off-by: Curtis Rueden <ctrueden@wisc.edu>

With Java 11 only (not 8, 17, or 21!), tests failed with errors like:

  java.lang.AssertionError:
    Unexpected: META-INF/maven/
            org.scijava.scripting.java
        /
            Dummy
        /pom.xml

Cause: the generated pom.xml has whitespace-polluted <groupId>,
<artifactId>, and <version> values.

Here's what was happening:

1. fakePOM() builds an XML document where each element's content is
   stored as a CDATA section via document.createCDATASection(content).

2. The transformer is configured with OutputKeys.INDENT = "yes".

3. In Java 8 (Xalan), the transformer writes CDATA content inline:
   <groupId><![CDATA[org.scijava.scripting.java]]></groupId>.

4. In Java 11, the internal XSLT transformer changed its indentation
   behavior for CDATA nodes — it treats a CDATA section as a child node
   distinct from inline text, and inserts a newline + indent before it
   and after it:

     <groupId>
         <![CDATA[org.scijava.scripting.java]]>
     </groupId>

5. When MiniMaven parses this POM back, getTextContent() on <groupId>
   returns "\n        org.scijava.scripting.java\n    ", which then gets
   embedded verbatim into the JAR entry path and into download URLs —
   causing the MalformedURLException and the wrong JAR entry names.

The fix is in the append method: replace createCDATASection with
createTextNode. XSLT transformers universally treat text-only elements
(those with a single text-node child and no element children) as opaque
and don't inject indentation whitespace inside them.

CDATA sections and text nodes are semantically identical in XML, but
Java 11's XSLT transformer treats a CDATA node as a distinct child and
wraps it with indentation whitespace when INDENT=yes. Plain text nodes
in text-only elements are left inline.

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

Signed-off-by: Curtis Rueden <ctrueden@wisc.edu>