fix: add missing git.lua for downloader

lua/blink/cmp/fuzzy/download/git.lua

@@ -0,0 +1,70 @@
+local async = require('blink.cmp.lib.async')
+local files = require('blink.cmp.fuzzy.download.files')
+local git = {}
+
+function git.get_version()
+  return async.task.await_all({ git.get_tag(), git.get_sha() }):map(
+    function(results)
+      return {
+        tag = results[1],
+        sha = results[2],
+      }
+    end
+  )
+end
+
+function git.get_tag()
+  return async.task.new(function(resolve, reject)
+    -- If repo_dir is nil, no git reposiory is found, similar to `out.code == 128`
+    local repo_dir = vim.fs.root(files.root_dir, '.git')
+    if not repo_dir then resolve() end
+
+    vim.system({
+      'git',
+      '--git-dir',
+      vim.fs.joinpath(repo_dir, '.git'),
+      '--work-tree',
+      repo_dir,
+      'describe',
+      '--tags',
+      '--exact-match',
+    }, { cwd = files.root_dir }, function(out)
+      if out.code == 128 then return resolve() end
+      if out.code ~= 0 then
+        return reject('While getting git tag, git exited with code ' .. out.code .. ': ' .. out.stderr)
+      end
+
+      local lines = vim.split(out.stdout, '\n')
+      if not lines[1] then return reject('Expected atleast 1 line of output from git describe') end
+      return resolve(lines[1])
+    end)
+  end)
+end
+
+function git.get_sha()
+  return async.task.new(function(resolve, reject)
+    -- If repo_dir is nil, no git reposiory is found, similar to `out.code == 128`
+    local repo_dir = vim.fs.root(files.root_dir, '.git')
+    if not repo_dir then resolve() end
+
+    vim.system({
+      'git',
+      '--git-dir',
+      vim.fs.joinpath(repo_dir, '.git'),
+      '--work-tree',
+      repo_dir,
+      'rev-parse',
+      'HEAD',
+    }, { cwd = files.root_dir }, function(out)
+      if out.code == 128 then return resolve() end
+      if out.code ~= 0 then
+        return reject('While getting git sha, git exited with code ' .. out.code .. ': ' .. out.stderr)
+      end
+
+      local sha = vim.split(out.stdout, '\n')[1]
+      return resolve(sha)
+    end)
+  end)
+end
+
+return git