feat(Algebra/Category/ModuleCat/Presheaf): the pushforward by a functor is monoidal

[joelriou]

If F : C ⥤ D is a functor and R : Dᵒᵖ ⥤ CommRingCat is a presheaf of commutative rings, then the pushforward functor from the category of presheaves of modules on R to the category of presheaves of modules on F.op ⋙ R is monoidal.

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[github-actions]

PR summary aa1dd647d3

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference
Mathlib.Algebra.Category.ModuleCat.Presheaf.PushforwardZeroMonoidal (new file)	1215

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Declarations diff

+ instance : (pushforward₀OfCommRingCat F R).Monoidal
+ pushforward₀OfCommRingCat

You can run this locally as follows

## summary with just the declaration names:
./scripts/pr_summary/declarations_diff.sh <optional_commit>

## more verbose report:
./scripts/pr_summary/declarations_diff.sh long <optional_commit>

The doc-module for scripts/pr_summary/declarations_diff.sh contains some details about this script.

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Increase in tech debt: (relative, absolute) = (1.00, 0.00)

Current number	Change	Type
10150	1	backward.isDefEq

Current commit c5bd28626f
Reference commit aa1dd647d3

You can run this locally as

./scripts/reporting/technical-debt-metrics.sh pr_summary

• The relative value is the weighted sum of the differences with weight given by the inverse of the current value of the statistic.
• The absolute value is the relative value divided by the total sum of the inverses of the current values (i.e. the weighted average of the differences).