Update dependency org.commonmark:commonmark to v0.26.0 (#1381)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

build.gradle

@@ -163,7 +163,7 @@ def versions = [
         authCheckerLib                  : '3.1.1',
         commonsBeanutils                : '1.11.0',
         commonsIO                       : '2.20.0',
-        commonMark                      : '0.25.1',
+        commonMark                      : '0.26.0',
         feign                           : '13.6',
         fortifyClient                   : '1.4.10',
         hmctsJavaLogging                : '6.1.9',