build: downgrade Tokio to 1.38 to fix Android compilation

Cargo.lock

@@ -3882,14 +3882,13 @@ dependencies = [
 
 [[package]]
 name = "mio"
-version = "1.0.1"
+version = "0.8.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4569e456d394deccd22ce1c1913e6ea0e54519f577285001215d33557431afe4"
+checksum = "a4a650543ca06a924e8b371db273b2756685faae30f8487da1b56505a8f78b0c"
 dependencies = [
- "hermit-abi",
  "libc",
  "wasi 0.11.0+wasi-snapshot-preview1",
- "windows-sys 0.52.0",
+ "windows-sys 0.48.0",
 ]
 
 [[package]]
@@ -6748,20 +6747,21 @@ checksum = "1f3ccbac311fea05f86f61904b462b55fb3df8837a366dfc601a0161d0532f20"
 
 [[package]]
 name = "tokio"
-version = "1.39.2"
+version = "1.38.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "daa4fb1bc778bd6f04cbfc4bb2d06a7396a8f299dc33ea1900cedaa316f467b1"
+checksum = "eb2caba9f80616f438e09748d5acda951967e1ea58508ef53d9c6402485a46df"
 dependencies = [
  "backtrace",
  "bytes",
  "libc",
  "mio",
+ "num_cpus",
  "parking_lot",
  "pin-project-lite",
  "signal-hook-registry",
  "socket2",
  "tokio-macros",
- "windows-sys 0.52.0",
+ "windows-sys 0.48.0",
 ]
 
 [[package]]
@@ -6776,9 +6776,9 @@ dependencies = [
 
 [[package]]
 name = "tokio-macros"
-version = "2.4.0"
+version = "2.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "693d596312e88961bc67d7f1f97af8a70227d9f90c31bba5806eec004978d752"
+checksum = "5f5ae998a069d4b5aba8ee9dad856af7d520c3699e6159b185c2acd48155d39a"
 dependencies = [
  "proc-macro2",
  "quote",

Cargo.toml

@@ -177,7 +177,14 @@ serde_json = "1"
 serde = "1.0"
 tempfile = "3.10.1"
 thiserror = "1"
-tokio = "1.39.2"
+
+# 1.38 is the latest version before `mio` dependency update
+# that broke compilation with Android NDK r23c and r24.
+# Version 1.39.0 cannot be compiled using these NDKs,
+# see issue <https://github.com/tokio-rs/tokio/issues/6748>
+# for details.
+tokio = "~1.38.1"
+
 tokio-util = "0.7.11"
 tracing-subscriber = "0.3"
 yerpc = "0.6.2"