No-op rename: remove metered from metered_scan_slice_of_slices (#…

…1058)

* No-op rename: remove `metered` from `metered_scan_slice_of_slices` as there is no metering.

This doesn't seem to need to be metered.

* Remove redundant TODO comment

soroban-env-host/src/host.rs

@@ -1228,7 +1228,7 @@ impl EnvBase for Host {
 
     fn symbol_index_in_strs(&self, sym: Symbol, slices: &[&str]) -> Result<U32Val, Self::Error> {
         let mut found = None;
-        self.metered_scan_slice_of_slices(slices, |i, slice| {
+        self.scan_slice_of_slices(slices, |i, slice| {
             if self.symbol_matches(slice.as_bytes(), sym)? && found.is_none() {
                 found = Some(i)
             }

soroban-env-host/src/host/mem_helper.rs

@@ -209,7 +209,7 @@ impl Host {
         Ok(())
     }
 
-    pub(crate) fn metered_scan_slice_of_slices(
+    pub(crate) fn scan_slice_of_slices(
         &self,
         slices: &[&str],
         mut callback: impl FnMut(usize, &str) -> Result<(), HostError>,
@@ -303,8 +303,6 @@ impl Host {
         let obj_end = obj_pos
             .checked_add(len)
             .ok_or_else(|| self.err_arith_overflow())? as usize;
-        // TODO: we currently grow the destination vec if it's not big enough,
-        // make sure this is desirable behaviour.
         if obj_new.len() < obj_end {
             self.charge_budget(
                 ContractCostType::HostMemAlloc,