git backend ignore replace objects (#18979) (#18980)

Co-authored-by: zeripath <art27@cantab.net>

modules/git/command.go

@@ -163,6 +163,8 @@ func (c *Command) RunWithContext(rc *RunContext) error {
 		fmt.Sprintf("LC_ALL=%s", DefaultLocale),
 		// avoid prompting for credentials interactively, supported since git v2.3
 		"GIT_TERMINAL_PROMPT=0",
+		// ignore replace references (https://git-scm.com/docs/git-replace)
+		"GIT_NO_REPLACE_OBJECTS=1",
 	)
 
 	// TODO: verify if this is still needed in golang 1.15