Remove FormatOrString and remaining uses of format()

src/libmain/progress-bar.cc

@@ -125,11 +125,11 @@ public:
         return printBuildLogs;
     }
 
-    void log(Verbosity lvl, const FormatOrString & fs) override
+    void log(Verbosity lvl, std::string_view s) override
     {
         if (lvl > verbosity) return;
         auto state(state_.lock());
-        log(*state, lvl, fs.s);
+        log(*state, lvl, s);
     }
 
     void logEI(const ErrorInfo & ei) override
@@ -142,7 +142,7 @@ public:
         log(*state, ei.level, oss.str());
     }
 
-    void log(State & state, Verbosity lvl, const std::string & s)
+    void log(State & state, Verbosity lvl, std::string_view s)
     {
         if (state.active) {
             writeToStderr("\r\e[K" + filterANSIEscapes(s, !isTTY) + ANSI_NORMAL "\n");