refactor!: remove go-git backend (#39487)

Removes the go-git backend so every build uses the git CLI backend. Its
Windows performance advantage is gone, it lacks SHA-256 support, and it
breaks repositories on Windows.

The performance changes moved to
https://github.com/go-gitea/gitea/pull/39526.

Fixes https://github.com/go-gitea/gitea/issues/38359
Fixes https://github.com/go-gitea/gitea/issues/34694

---------

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

tools/build-release.sh

@@ -13,12 +13,9 @@ RELEASE_PLATFORMS_DEFAULT=(
   freebsd/amd64
 )
 
-RELEASE_PLATFORMS_GOGIT=(windows/amd64 windows/arm64)
-
 build() {
   echo "building ${*} ..."
   local target="${1:?}"
-  local variant="${2:-}"
 
   local goos="${target%%/*}"
   local goarch="${target##*/}"
@@ -28,21 +25,12 @@ build() {
     goarch="arm"
   fi
 
-  local tags="${RELEASE_TAGS}"
-  local suffix
-  if [[ "$variant" == "gogit" ]]; then
-    tags="gogit${tags:+ ${tags}}"
-    suffix="-gogit-${target//\//-}"
-  else
-    suffix="-${target//\//-}"
-  fi
-
-  local output="${RELEASE_PATH_PREFIX}${suffix}"
+  local output="${RELEASE_PATH_PREFIX}-${target//\//-}"
   local args=()
   if [[ "$goos" == "windows" ]]; then
     output="${output}.exe"
   fi
-  args+=(-tags "$tags")
+  args+=(-tags "$RELEASE_TAGS")
   args+=(-ldflags "$RELEASE_LDFLAGS")
   echo "  args: ${args[*]}"
   echo "  output: ${output}"
@@ -61,16 +49,6 @@ main() {
       build "$target"
     fi
   done
-
-  # Only build with gogit for main-nightly, disable gogit for stable releases since there seems no real requirement for them.
-  # If no real requirement (no user feedbacks), we can completely remove gogit support in the future.
-  if [ "$VERSION" = "main-nightly" ]; then
-    for target in "${RELEASE_PLATFORMS_GOGIT[@]}"; do
-      if [[ -z "$platform" || "$target" == "$platform/"* ]]; then
-        build "$target" "gogit"
-      fi
-    done
-  fi
 }
 
 main "$@"

tools/lint-go-all.go

@@ -122,7 +122,7 @@ func main() {
 	if os.Getenv("CI") != "" {
 		// only lint for other platforms when in CI, to keep local lint fast
 		_, _ = fmt.Fprintln(os.Stdout, "lint for windows ...")
-		succeed = runCmd([]string{"GOOS=windows", "TAGS=gogit"}, "golangci-lint", append([]string{"run", "--build-tags=windows,gogit"}, os.Args[1:]...)) && succeed
+		succeed = runCmd([]string{"GOOS=windows"}, "golangci-lint", append([]string{"run", "--build-tags=windows"}, os.Args[1:]...)) && succeed
 	}
 
 	if !succeed {