It is not correct to return tag data when commit data is requested, so
remove the hacky code that overwrote parts of a commit with parts of a
tag.

This fixes commit retrieval by tag for both the latest commit in the UI
and the commit info on tag webhook events.

Fixes: https://github.com/go-gitea/gitea/issues/21687
Replaces: https://github.com/go-gitea/gitea/pull/21693

<img width="324" alt="Screenshot 2022-11-13 at 15 26 37"
src="https://user-images.githubusercontent.com/115237/201526975-736c6ea7-ad6a-467a-a823-9a63d6ecb718.png">

<img width="789" alt="image"
src="https://user-images.githubusercontent.com/115237/201526876-90a13ffc-1e5c-4d76-911b-f1ae51e8eaab.png">

---------

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

Fix #13485.

Co-authored-by: delvh <dev.lh@web.de>
Co-authored-by: Lauris BH <lauris@nix.lv>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

Change all license headers to comply with REUSE specification.

Fix #16132

Co-authored-by: flynnnnnnnnnn <flynnnnnnnnnn@github>
Co-authored-by: John Olheiser <john.olheiser@gmail.com>

Follow #21464

Make all git command arguments strictly safe. Most changes are one-to-one replacing, keep all existing logic.

Go 1.17 and later use modern `//go:build` constraints, the old `// +build:` constraints should be removed.

Follows #19266, #8553, Close #18553, now there are only three `Run..(&RunOpts{})` functions.
 * before: `stdout, err := RunInDir(path)`
 * now: `stdout, _, err := RunStdString(&git.RunOpts{Dir:path})`

Git will and can pack references into packfiles and therefore if you write/read the
files directly you will get false results. Instead you should use update-ref and
show-ref. To that end I have created three new functions in git/repo_commit.go that
will do this correctly.

Related #17191

Signed-off-by: Andrew Thornton <art27@cantab.net>

This PR registers requests with the process manager and manages hierarchy within the processes.

Git repos are then associated with a context, (usually the request's context) - with sub commands using this context as their base context.

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Add bundle download

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Fix fmt

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Fix build tags

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Download specific commit

Signed-off-by: jolheiser <john.olheiser@gmail.com>

Use common git cat-file --batch and git cat-file --batch-check to
significantly reduce calls to git.
    
Signed-off-by: Andrew Thornton <art27@cantab.net>

* Move last commit cache back into modules/git

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Remove go-git from the interface for last commit cache

Signed-off-by: Andrew Thornton <art27@cantab.net>

* move cacheref to last_commit_cache

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Remove go-git from routers/private/hook

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Move FindLFSFiles to pipeline

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Make no-go-git variants

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Submodule RefID

Signed-off-by: Andrew Thornton <art27@cantab.net>

* fix issue with GetCommitsInfo

Signed-off-by: Andrew Thornton <art27@cantab.net>

* fix GetLastCommitForPaths

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Improve efficiency

Signed-off-by: Andrew Thornton <art27@cantab.net>

* More efficiency

Signed-off-by: Andrew Thornton <art27@cantab.net>

* even faster

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Reduce duplication

* As per @lunny

Signed-off-by: Andrew Thornton <art27@cantab.net>

* attempt to fix drone

Signed-off-by: Andrew Thornton <art27@cantab.net>

* fix test-tags

Signed-off-by: Andrew Thornton <art27@cantab.net>

* default to use no-go-git variants and add gogit build tag

Signed-off-by: Andrew Thornton <art27@cantab.net>

* placate lint

Signed-off-by: Andrew Thornton <art27@cantab.net>

* as per @6543

Signed-off-by: Andrew Thornton <art27@cantab.net>

Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: techknowlogick <techknowlogick@gitea.io>