Add Dockerfile and docs for building Cloudberry Docker Images #3601

Job	Run time
check-skip	3s
Build Apache Cloudberry RPM	13m 41s
prepare-test-matrix	3s
RPM Install Test Apache Cloudberry	2m 4s
pax-ic-isolation2-opt-on	24m 0s
ic-diskquota	10m 40s
ic-resgroup-v2	20m 27s
pax-ic-good-opt-on	27m 11s
ic-expandshrink	4m 25s
ic-fixme	3m 45s
ic-isolation2-hot-standby	4m 4s
ic-cbdb-parallel	28m 8s
ic-contrib	3m 58s
ic-isolation2	36m 36s
pax-ic-good-opt-off	22m 50s
ic-singlenode	8m 31s
pax-ic-isolation2-opt-off	23m 14s
ic-gpcontrib	4m 26s
ic-parallel-retrieve-cursor	5m 8s
ic-isolation2-crash	4m 41s
ic-good-opt-off	25m 59s
ic-good-opt-on	28m 39s
Generate Apache Cloudberry Build Report	2s
	5h 2m 35s

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