chore: extend the default `block_proposal_timeout` to 4 hours #4090

Job	Run time
Check Access Permissions	2s
Check Packages and Shards	1m 32s
Mutation Testing - Normal, Stackslib	0s
Mutation Testing - Shards, Small	0s
Mutation Testing - Normal, Small	0s
Mutation Testing - Shards, Stackslib	0s
Mutation Testing - Normal, Stacks Node	0s
Mutation Testing - Shards, Stacks Node	0s
Mutation Testing - Normal, Stacks Signer	0s
Output Mutants	2s
	1m 36s

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