dev.Dockerfile: allow forcing an lnd version #2537

Job	Run time
frontend tests on macOS-latest	2m 14s
frontend tests on windows-latest	6m 56s
frontend tests on ubuntu-latest	2m 18s
backend build on windows-latest	15m 53s
backend build on ubuntu-latest	10m 35s
lint	5m 18s
backend build on macOS-latest	8m 47s
Sqlc check	45s
run unit tests (unit)	4m 42s
integration test (bbolt, itest-no-backward-compat icase=terminal dbbackend=bbolt)	10m 5s
run unit tests (unit-race)	6m 44s
integration test (custom-channels, itest-only icase=custom_channels)	19m 0s
integration test (sqlite, itest-no-backward-compat icase=terminal dbbackend=sqlite)	10m 18s
cross compilation (arm, darwin-arm64 linux-armv6 linux-armv7 linux-arm64)	17m 52s
check release notes updated	4s
check commits	4m 12s
integration test (postgres, itest-no-backward-compat icase=terminal dbbackend=postgres)	11m 49s
run unit tests (unit dbbackend=sqlite)	4m 48s
RPC proto compilation check	3m 29s
cross compilation (i386, linux-386)	5m 10s
run unit tests (unit dbbackend=postgres)	5m 40s
cross compilation (amd64, darwin-amd64 linux-amd64 windows-amd64)	13m 16s
	2h 49m 55s

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