Remove unused headers

Remove some headers that are very obviously unused.

Change-Id: I2c55b84b8ba678caad622f3c115e67d923c72a4a
Signed-off-by: Matt Spinler <spinler@us.ibm.com>
diff --git a/log_manager.cpp b/log_manager.cpp
index bd902c3..e4c38d2 100644
--- a/log_manager.cpp
+++ b/log_manager.cpp
@@ -22,10 +22,7 @@
 #include <chrono>
 #include <cstdio>
 #include <cstring>
-#include <fstream>
 #include <functional>
-#include <future>
-#include <iostream>
 #include <map>
 #include <ranges>
 #include <set>