build(deps): bump mockery v2.53.6 → v3.7.2

[DoDiODev]

Summary

Bumps the mock-generation tool github.com/vektra/mockery from v2.53.6 to
v3.7.2 at every install site (backend/Makefile, backend/Dockerfile,
backend/Dockerfile.local, devops/docker/lake-builder/Dockerfile), and adds
the two YAML configs mockery v3 requires instead of CLI flags.

Current pinning (before this PR) is mockery v2.53.6 (released 2024); v3.7.2 is
a rewrite with a new CLI/config surface (no code-generation logic changes for
the mocks actually used by this repo — see "Behavioral changes" below).

What changed

File	Change
backend/Makefile (go-dep, mock)	mockery@v2.53.6 → @v3.7.2; mock target invokes the two new configs in a fixed order
backend/Dockerfile	install site v2.53.6 → v3.7.2
backend/Dockerfile.local	ditto
devops/docker/lake-builder/Dockerfile	ditto
backend/.mockery.core.yml (new)	v3 config for core/ + helpers/pluginhelper/subtaskmeta/sorter, reproducing the v2 layout 1:1
backend/.mockery.helpers.yml (new)	v3 config for the remaining helpers/ interfaces

Why two configs? helpers/unithelper imports the generated
mocks/core/... packages. Unlike v2, v3 loads sources via go/packages
with type-checking, so the core mocks must exist before the helpers
tree is parsed. A single run across both trees fails after rm -rf mocks
with could not import .../mocks/core/... (invalid package name). Both
configs reproduce the v2 layout 1:1 (dir: mocks/{{.InterfaceDirRelative}},
filename: {{.InterfaceName}}.go, pkgname: mocks,
structname: {{.InterfaceName}}, template: testify,
template-data.unroll-variadic: false), so existing imports such as
mockdal "github.com/apache/incubator-devlake/mocks/core/dal" stay valid.

Behavioral changes of v3 (documented for reviewers)

1. No generated-code churn to review: backend/mocks/ is untracked (see
   .gitignore), so this diff is exactly the 6 files listed above — nothing
   under backend/mocks/ is part of the PR.
2. Function-type mocking is gone, interfaces only: 13 mocks disappear
   (e.g. plugin.ApiAsyncCallback, plugin.ApiResourceHandler,
   plugin.SubTaskEntryPoint, api.DataConvertHandler,
   api.DsListRemoteScopes, errors.Option). None of them is referenced by
   any test (verified via grep over all *_test.go files). Generated file
   count drops from 77 to 64.
3. template-data.with-expecter is no longer a valid key: v3 always
   generates EXPECT()-style expectations — purely additive, no test changes
   needed.
4. CLI flags are gone: --recursive/--keeptree/--dir/--output/--name no
   longer exist; configuration is YAML-only, hence the two new config files.

Validation

CI equivalent (all green): the identical job matrix was run in a fork
workflow (fork-ci.yml) on ci/wave4e (this branch, unchanged) —
run 30904038830,
8/8 jobs successful: builder image, lint (go), unit-test, e2e (mysql),
migration-script-lint, config-ui, ASF license header, grafana dashboards.

Additionally, locally on macOS (arm64), against the unmodified
upstream/main toolchain (git2go v33 / libgit2 1.3.x — this PR does not touch
that pairing, see "Out of scope"):

• ✅ make mock — regenerates all 64 mock files cleanly (rm -rf mocks +
  both configs in order)
• ✅ go build ./... — compiles
• ✅ ./scripts/unit-test-go.sh — 64 packages, exit 0, no failures
• ✅ make migration-script-lint

Out of scope on purpose

• backend/plugins/gitextractor / libgit2 / git2go pinning — unrelated,
  covered by the separate build(deps): bump libgit2 1.3 → 1.5.0 and git2go v33 → v34 #9028 (Welle 4d).
• Any change to backend/mocks/** — untracked, not part of the diff.

Rollback

Revert the four version hunks, delete the two .mockery.*.yml files, restore
the mock target's v2 CLI flags. No runtime, schema, or API impact —
backend/mocks/ is generated and untracked either way.