fix(tippecanoe): use GHCR registry for GDAL image (migrated from Docker Hub)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tippecanoe.Dockerfile

@@ -6,7 +6,7 @@ WORKDIR /src/tippecanoe
 RUN make -j$(nproc) && make install
 
 # Stage 2: runtime with GDAL + tippecanoe + mc
-FROM osgeo/gdal:alpine-normal-latest
+FROM ghcr.io/osgeo/gdal:alpine-normal-latest
 
 COPY --from=builder /usr/local/bin/tippecanoe /usr/local/bin/tippecanoe
 COPY --from=builder /usr/local/bin/tile-join /usr/local/bin/tile-join