vim-patch.sh: remove version.c in generated patch

Vim patch tracking is now driven completely by `vim-patch:xxx` tokens in
the VCS logs. version.c will be auto-generated, if it is used at all.

scripts/vim-patch.sh

@@ -148,6 +148,10 @@ preprocess_patch() {
 
   # Remove some testdir/Make_*.mak files
   local na_src_testdir='Make_amiga.mak\|Make_dos.mak\|Make_ming.mak\|Make_vms.mms'
+  2>/dev/null $nvim --cmd 'set dir=/tmp' +'g@^diff --git a/src/testdir/\<\%('${na_src_testdir}'\)\>@norm! d/\v(^diff)|%$
+' +w +q "$file"
+
+  # Remove version.c #7555
   local na_po='version.c'
   2>/dev/null $nvim --cmd 'set dir=/tmp' +'g@^diff --git a/src/\<\%('${na_po}'\)\>@norm! d/\v(^diff)|%$
 ' +w +q "$file"