ignore .DS_Store files [skip ci] (danmar#7577)

These files are autogenerated by the Finder (the Explorer on macOS)

Author: autoantwort

.gitignore

@@ -15,6 +15,7 @@ tags
 tools/daca2*.html
 tools/errmsg
 tools/extracttests
+.DS_Store
 
 # dump files generated by Cppcheck
 *.*.dump
@@ -125,4 +126,4 @@ stage
 
 # PCRE Windows files
 /externals/pcre.h
-/externals/pcre64.lib
+/externals/pcre64.lib