refactor: replace num_cpus with thread::available_parallelism (#526)

Author: SteveLauC

Cargo.toml

@@ -66,7 +66,6 @@ itertools = "0.13"
 log = "^0.4"
 mockito = "^1"
 murmur3 = "0.5.2"
-num_cpus = "1"
 once_cell = "1"
 opendal = "0.48"
 ordered-float = "4.0.0"

crates/iceberg/Cargo.toml

@@ -61,7 +61,6 @@ fnv = { workspace = true }
 futures = { workspace = true }
 itertools = { workspace = true }
 murmur3 = { workspace = true }
-num_cpus = { workspace = true }
 once_cell = { workspace = true }
 opendal = { workspace = true }
 ordered-float = { workspace = true }

crates/iceberg/src/scan.rs

@@ -61,7 +61,9 @@ pub struct TableScanBuilder<'a> {
 
 impl<'a> TableScanBuilder<'a> {
     pub(crate) fn new(table: &'a Table) -> Self {
-        let num_cpus = num_cpus::get();
+        let num_cpus = std::thread::available_parallelism()
+            .expect("failed to get number of CPUs")
+            .get();
 
         Self {
             table,