[Backport next] site: remove *GLUON_RELEASE #725

Job	Run time
generate_target_matrix	3s
build_firmware (armsr-armv7)	1h 16m 38s
build_firmware (armsr-armv8)	1h 27m 32s
build_firmware (ath79-generic)	1h 20m 22s
build_firmware (ath79-mikrotik)	1h 15m 57s
build_firmware (ath79-nand)	1h 15m 21s
build_firmware (bcm27xx-bcm2708)	1h 10m 11s
build_firmware (bcm27xx-bcm2709)	1h 17m 30s
build_firmware (bcm27xx-bcm2710)	1h 24m 3s
build_firmware (bcm27xx-bcm2711)	1h 23m 19s
build_firmware (ipq40xx-generic)	1h 19m 17s
build_firmware (ipq40xx-mikrotik)	1h 17m 40s
build_firmware (ipq806x-generic)	1h 17m 58s
build_firmware (kirkwood-generic)	1h 14m 55s
build_firmware (lantiq-xrx200)	1h 21m 44s
build_firmware (lantiq-xway)	1h 16m 7s
build_firmware (mediatek-filogic)	1h 26m 20s
build_firmware (mediatek-mt7622)	1h 23m 4s
build_firmware (mpc85xx-p1010)	1h 16m 8s
build_firmware (mpc85xx-p1020)	1h 16m 54s
build_firmware (mvebu-cortexa9)	1h 15m 56s
build_firmware (ramips-mt7620)	1h 16m 13s
build_firmware (ramips-mt7621)	1h 20m 54s
build_firmware (ramips-mt76x8)	1h 16m 47s
build_firmware (realtek-rtl838x)	1h 3m 20s
build_firmware (rockchip-armv8)	1h 24m 26s
build_firmware (sunxi-cortexa7)	1h 10m 37s
build_firmware (x86-64)	1h 30m 53s
build_firmware (x86-generic)	1h 26m 41s
build_firmware (x86-geode)	1h 22m 34s
build_firmware (x86-legacy)	1h 24m 54s
create_release	0s
	1d 15h 34m 18s

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