treewide: remove unnecessary cache.h includes in source files

We had several C files include cache.h unnecessarily.  Replace those
with an include of "git-compat-util.h" instead.  Much like the previous
commit, these have all been verified via both ensuring that
    gcc -E $SOURCE_FILE | grep '"cache.h"'
found no hits and that
    make DEVELOPER=1 ${OBJECT_FILE_FOR_SOURCE_FILE}
successfully compiles without warnings.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

trace2.c

@@ -1,4 +1,4 @@
-#include "cache.h"
+#include "git-compat-util.h"
 #include "config.h"
 #include "json-writer.h"
 #include "quote.h"
@@ -6,6 +6,7 @@
 #include "sigchain.h"
 #include "thread-utils.h"
 #include "version.h"
+#include "trace.h"
 #include "trace2/tr2_cfg.h"
 #include "trace2/tr2_cmd_name.h"
 #include "trace2/tr2_ctr.h"