patch 8.1.0576: indent script tests pick up installed scripts

Problem:    Indent script tests pick up installed scripts.
Solution:   Use current runtime indent scripts.
diff --git a/runtime/indent/Makefile b/runtime/indent/Makefile
index 3791f33..1917e46 100644
--- a/runtime/indent/Makefile
+++ b/runtime/indent/Makefile
@@ -1,13 +1,14 @@
 # Portable Makefile for running indent tests.
 
 VIM = vim
+VIMRUNTIME = ..
 
 # Run the tests that didn't run yet or failed previously.
 # If a test succeeds a testdir/*.out file will be written.
 # If a test fails a testdir/*.fail file will be written.
 test:
-	$(VIM) --clean --not-a-term -u testdir/runtest.vim
+	VIMRUNTIME=$(VIMRUNTIME) $(VIM) --clean --not-a-term -u testdir/runtest.vim
 
 
 clean:
-	$(VIM) --clean --not-a-term -u testdir/cleantest.vim
+	VIMRUNTIME=$(VIMRUNTIME) $(VIM) --clean --not-a-term -u testdir/cleantest.vim
diff --git a/src/version.c b/src/version.c
index 981d918..29fdfb2 100644
--- a/src/version.c
+++ b/src/version.c
@@ -793,6 +793,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    576,
+/**/
     575,
 /**/
     574,