deps: bump bdk to beta_6 #1168

Job	Run time
Build and test macOS arm64 wheels (3.8)	8m 51s
Build and test macOS x86_64 wheels (3.8)	5m 9s
Build and test macOS arm64 wheels (3.9)	9m 49s
Build and test macOS x86_64 wheels (3.9)	5m 18s
Build and test macOS arm64 wheels (3.10)	4m 47s
Build and test macOS x86_64 wheels (3.10)	8m 44s
Build and test Manylinux 2.28 x86_64 wheels (cp38-cp38)	3m 47s
Build and test macOS arm64 wheels (3.11)	7m 6s
Build and test Windows wheels (3.8)	6m 23s
Build and test Manylinux 2.28 x86_64 wheels (cp39-cp39)	4m 5s
Build and test macOS x86_64 wheels (3.11)	5m 44s
Build and test macOS arm64 wheels (3.12)	4m 30s
Build and test Manylinux 2.28 x86_64 wheels (cp310-cp310)	4m 2s
Build and test Windows wheels (3.9)	6m 28s
Build and test macOS x86_64 wheels (3.12)	5m 1s
Build and test Manylinux 2.28 x86_64 wheels (cp311-cp311)	3m 45s
Build and test Windows wheels (3.10)	6m 22s
Build and test Manylinux 2.28 x86_64 wheels (cp312-cp312)	3m 42s
Build and test Windows wheels (3.11)	6m 10s
Build and test Windows wheels (3.12)	5m 47s
	1h 55m 30s

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