Bump ExecuTorch release version to 1.3.0 (#8117)

Updates `EXECUTORCH_VERSION` in `release/release_versions.sh` from
`1.2.0` to `1.3.0` for the ExecuTorch 1.3 release.

Test plan: not run; version constant update only.

Author: JacobSzwejbka

release/release_versions.sh

@@ -9,7 +9,7 @@ TORCHCOMMS_VERSION=${TORCHCOMMS_VERSION:-0.2.0}
 TRITON_VERSION=${TRITON_VERSION:-3.3.0}
 TORCHTEXT_VERSION=${TORCHTEXT_VERSION:-0.18.0}
 TORCHREC_VERSION=${TORCHREC_VERSION:-1.5.0}
-EXECUTORCH_VERSION=${EXECUTORCH_VERSION:-1.2.0}
+EXECUTORCH_VERSION=${EXECUTORCH_VERSION:-1.3.0}
 TORCH_TENSORRT_VERSION=${TORCH_TENSORRT_VERSION:-2.12.0}
 TORCH_TENSORRT_RTX_VERSION=${TORCH_TENSORRT_VERSION}
 TORCHAO_VERSION=${TORCHAO_VERSION:-0.17.0}