Add Neumann BC in the LinearFV system #30146

[freiler]

Closes #30146

[moosebuild]

Job Documentation, step Docs: sync website on 438a673 wanted to post the following:

View the site here

This comment will be updated on new commits.

[moosebuild]

Job Coverage, step Generate coverage on 438a673 wanted to post the following:

Framework coverage

	051868	#30147 438a67
	Total	Total	+/-	New
Rate	85.29%	85.29%	-0.00%	-
Hits	109056	109055	-1	0
Misses	18809	18810	+1	0

Diff coverage report

Full coverage report

Modules coverage

Coverage did not change

Full coverage reports

Reports

• framework
• chemical_reactions
• combined
• contact
• electromagnetics
• external_petsc_solver
• fluid_properties
• fsi
• functional_expansion_tools
• geochemistry
• heat_transfer
• level_set
• misc
• navier_stokes
• optimization
• peridynamics
• phase_field
• porous_flow
• ray_tracing
• rdg
• reactor
• richards
• scalar_transport
• solid_mechanics
• solid_properties
• stochastic_tools
• subchannel
• thermal_hydraulics
• xfem

This comment will be updated on new commits.

[moosebuild]

Job Precheck, step Clang format on 316740c wanted to post the following:

Your code requires style changes.

A patch was auto generated and copied here
You can directly apply the patch by running, in the top level of your repository:

curl -s https://mooseframework.inl.gov/docs/PRs/30147/clang_format/style.patch | git apply -v

Alternatively, with your repository up to date and in the top level of your repository:

git clang-format 92e4cfa047ab08e7fab70c0d4c297b858ba6905d