Do not require libde265 at configure time

[kel-mo]

src/ includes kodi/addon-instance/ImageDecoder.h, libheif/heif_cxx.h and TinyEXIF — never libde265/de265.h. git log -S libde265 -- src/ lib/ returns nothing, so the REQUIRED has been vestigial for the life of the add-on.

It does have a cost: it prevents configuring against a system libheif that supplies HEVC on its own. freedesktop-sdk 26.08 ships libheif 1.23.1 with plugin loading enabled and provides libheif-libde265.so through the codecs-extra extension; Debian splits the decoder out into libheif-plugin-libde265 the same way. In those environments libde265 need not be visible to this add-on at all.

This only drops REQUIRED. ${de265_INCLUDE_DIRS} and ${de265_LIBRARIES} are left in place, so wherever libde265 is found — including Kodi's own depends builds, where FindHEIF.cmake resolves a static libheif and cannot pick up transitive libraries from pkg-config — the include path and link line are byte-for-byte unchanged.

Testing: built in the Flathub tv.kodi.Kodi manifest against freedesktop-sdk 26.08 with the bundled libheif and libde265 modules removed. The resulting imagedecoder.heif.so lists only libheif.so.1 (plus tinyxml2 and libc) in DT_NEEDED. Four HEIC images display correctly in Kodi 22: 4032×3024 and 4000×3000 grid-tiled files of 48 HEVC tiles each, 8-bit 4:2:0, profiles Main and Main Still Picture, exercising tile assembly, embedded thumbnails, EXIF and irot rotation.

[greptile-apps]

Greptile Summary

The PR makes direct libde265 discovery optional, allowing configuration when libheif supplies HEVC decoding independently while preserving de265 include and link variables when discovery succeeds.

• Removes REQUIRED from find_package(de265).
• Retains the existing de265 include-directory and library references.

Confidence Score: 5/5

The PR appears safe to merge, with no concrete changed-code-triggered failures identified.

Optional discovery continues cleanly when libde265 is absent and preserves explicit linkage when it is found; no supported repository build path was shown to require an undiscoverable direct libde265 dependency.

Important Files Changed

Filename	Overview
CMakeLists.txt	Makes libde265 optional without otherwise changing dependency ordering or the addon's link composition.

_{Reviews (1): Last reviewed commit: "Do not require libde265 at configure tim..." | Re-trigger Greptile}