Revert "fix: skip miri tests for zstd due to ffi"

This reverts commit 868f0dc.

Author: morrisonlevi

datadog-profiling/src/internal/observation/observations.rs

@@ -189,7 +189,7 @@ impl IntoIterator for Observations {
     }
 }
 
-#[cfg(all(test, not(miri)))]
+#[cfg(test)]
 mod tests {
     use super::*;
     use crate::collections::identifiable::*;

datadog-profiling/src/internal/profile/mod.rs

@@ -910,7 +910,7 @@ impl Profile {
     }
 }
 
-#[cfg(all(test, not(miri)))]
+#[cfg(test)]
 mod api_tests {
     use super::*;
     use crate::pprof::test_utils::{roundtrip_to_pprof, sorted_samples, string_table_fetch};