at91: drop 6.1 support #2527

Job	Run time
Build all affected Kernels / Determine Changed Files / Determine Changed Files	8s
Build all affected Kernels / Set targets	36s
Build all affected Kernels / Determine Changed Packages / Determine Changed Packages	6s
Build all affected Kernels / Build Kernel with external toolchain (at91, sama5) / Set up build at91/sama5	4s
Build all affected Kernels / Check Kernel patches (at91, sam9x) / Set up build	1s
Build all affected Kernels / Build Kernel with external toolchain (at91, sama7) / Set up build at91/sama7	6s
Build all affected Kernels / Build Kernel with external toolchain (at91, sam9x) / Set up build at91/sam9x	5s
Build all affected Kernels / Build Kernel with external toolchain (at91, sama5) / Build at91/sama5	9m 40s
Build all affected Kernels / Build Kernel with external toolchain (at91, sama5) / Check packages for at91/sama5	4m 21s
Build all affected Kernels / Build Kernel with external toolchain (at91, sam9x) / Build at91/sam9x	3m 48s
Build all affected Kernels / Build Kernel with external toolchain (at91, sam9x) / Check packages for at91/sam9x	3m 6s
Build all affected Kernels / Check Kernel patches (at91, sam9x) / Check Kernel patches	3m 17s
Build all affected Kernels / Build Kernel with external toolchain (at91, sama7) / Build at91/sama7	10m 22s
Build all affected Kernels / Build Kernel with external toolchain (at91, sama7) / Check packages for at91/sama7	3m 2s
Build all affected Kernels / Upload ccache cache to s3	0s
	38m 42s

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