feat(Combinatorics/GraphLike): Digraph is GraphLike

[Jun2M]

Digraph has GraphLike instance.

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• depends on: feat(Combinatorics/GraphLike): introduce GraphLike typeclass #36743
• depends on: feat(Combinatorics/GraphLike): GraphLike with no multi edges #39047

[github-actions]

PR summary cc11377b60

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference
Mathlib.Combinatorics.GraphLike.Basic (new file)	489
Mathlib.Combinatorics.Digraph.GraphLike (new file)	527

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Declarations diff

+ Adj.left_mem
+ Adj.right_mem
+ DartAdj
+ GraphLike
+ NoMultiEdgeGraphLike
+ adj_source_target
+ dart_eq_of_src_tgt_eq
+ darts_ext
+ instance : NoMultiEdgeGraphLike V (V × V) (V × V) (Digraph V)
+ instance [DecidableRel (Adj G)] : DecidablePred (· ∈ darts G)
+ mem_darts_iff_adj
+ src_tgt_inj
+ toProd
+ toProd_eq

You can run this locally as follows

## from your `mathlib4` directory:
git clone https://github.com/leanprover-community/mathlib-ci.git ../mathlib-ci

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

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

The doc-module for scripts/pr_summary/declarations_diff.sh in the mathlib-ci repository contains some details about this script.

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No changes to strong technical debt.

No changes to weak technical debt.

[mathlib-dependent-issues]

This PR/issue depends on:

• feat(Combinatorics/GraphLike): introduce GraphLike typeclass #36743
• feat(Combinatorics/GraphLike): GraphLike with no multi edges #39047
  By Dependent Issues (🤖). Happy coding!