dev-vcs/tig: restore tab completion

The patch applied in the last bump is incorrect and effectively disables
bash completion no matter what order the completions were loaded in as
`type -f` will not find `__git_complete`.

```
$ type -f __git_complete
bash: type: __git_complete: not found
$ type __git_complete | grep 'is a'
__git_complete is a function
```

There is a pull-request upstream that properly addresses the issue of
`__git_complete` not being found but it's not accepted yet,
https://github.com/jonas/tig/pull/1016

Package-Manager: Portage-3.0.4, Repoman-3.0.1
Signed-off-by: Justin Bronder <jsbronder@cold-front.org>
Closes: https://github.com/gentoo/gentoo/pull/17715
Signed-off-by: Georgy Yakovlev <gyakovlev@gentoo.org>

dev-vcs/tig/files/tig-2.5.1-bash-completion-qa-warning.patch

@@ -1,15 +0,0 @@
-diff --git a/contrib/tig-completion.bash b/contrib/tig-completion.bash
-index 5aef3fd..cec0632 100755
---- a/contrib/tig-completion.bash
-+++ b/contrib/tig-completion.bash
-@@ -29,6 +29,10 @@
- #       at source time then all lookups will be done on demand,
- #       which may be slightly slower.
- 
-+if ! type -f __git_complete &>/dev/null; then
-+	__git_complete() { complete "${1}"; }
-+fi
-+
- __tig_options="
- 	-v --version
- 	-h --help

dev-vcs/tig/tig-2.5.1.ebuild

@@ -31,10 +31,6 @@ RDEPEND="${DEPEND}
 # encoding/env issues
 RESTRICT="test"
 
-PATCHES=(
-	"${FILESDIR}/tig-2.5.1-bash-completion-qa-warning.patch"
-)
-
 src_prepare() {
 	default
 	[[ ${PV} == "9999" ]] && eautoreconf