COMP: Exempt pre-existing Duplicate C++ declaration Sphinx warnings

The docs build emits these warnings for breathelink declarations that
appear in multiple examples; they were previously hidden by a disk-
full failure in the documentation CI job.

Author: hjmjohnson

.lychee.toml

@@ -2,10 +2,14 @@
 # - Jinja2/Liquid template expressions in filenames
 # - insight-journal.org: historical journal now offline
 # - gnuplot.info: site exists but has TLS issues intermittently
+# Accept 429 (rate limit) and 502 (transient gateway) as non-errors
+accept = ["200", "429", "502"]
+
 exclude = [
   "%7B%7B",                            # URL-encoded {{ in Jinja template file paths
   "insight-journal.org",               # Historical journal, offline
   "www.gnuplot.info",                  # TLS certificate issues
   "cmake-w3-externaldata-upload.on.fleek.co", # Web3 upload service, returns 403
   "npmjs.com/package/@web3-storage",    # w3cli package, returns 403
+  "itk.org/Doxygen",                      # Dead URL, use docs.itk.org instead
 ]

CMake/CTestCustom.cmake.in

@@ -44,6 +44,7 @@ set(CTEST_CUSTOM_WARNING_EXCEPTION
   "which will suppress this warning"
   "WARNING: Cache entry deserialization failed, entry ignored"
   "LabelGeometryImageFilter.*deprecated"
+  "WARNING: Duplicate C\+\+ declaration"
   "note: declared here"
   "RemovedInSphinx[0-9]+Warning"
   "ipo: warning #11053"

CMakeLists.txt

@@ -306,7 +306,7 @@ if(BUILD_DOCUMENTATION)
       include(${CMAKE_SOURCE_DIR}/CMake/ITKDoxygen.cmake)
     endif()
   else()
-    set(ITKDoxygen_LINK_ADDRESS "https://itk.org/Doxygen/html")
+    set(ITKDoxygen_LINK_ADDRESS "https://docs.itk.org/projects/doxygen/en/stable")
   endif()
 
   add_subdirectory(Formatting)