ci: add riscv64gc-unknown-linux-gnu to release binaries

Add riscv64gc-unknown-linux-gnu to both publish_dev_release and
publish_tagged_release build matrices, using cross for cross-compilation.
Add corresponding Cross.toml entry with OpenSSL configuration.

Author: gounthar

.github/workflows/publish-binaries.yml

@@ -33,6 +33,9 @@ jobs:
           - rust-target: aarch64-unknown-linux-gnu
             os: ubuntu-latest
             cross: true
+          - rust-target: riscv64gc-unknown-linux-gnu
+            os: ubuntu-latest
+            cross: true
           - rust-target: x86_64-apple-darwin
             os: macos-latest
           - rust-target: aarch64-apple-darwin
@@ -89,6 +92,9 @@ jobs:
           - rust-target: aarch64-unknown-linux-gnu
             os: ubuntu-latest
             cross: true
+          - rust-target: riscv64gc-unknown-linux-gnu
+            os: ubuntu-latest
+            cross: true
           - rust-target: x86_64-apple-darwin
             os: macos-latest
           - rust-target: aarch64-apple-darwin

Cross.toml

@@ -9,3 +9,15 @@ env.passthrough = [
     "OPENSSL_STATIC=yes"
 ]
 image = "ghcr.io/cross-rs/aarch64-unknown-linux-gnu:edge"
+
+[target.riscv64gc-unknown-linux-gnu]
+pre-build = [
+    "dpkg --add-architecture $CROSS_DEB_ARCH",
+    "apt-get update && apt-get --assume-yes install libssl-dev:$CROSS_DEB_ARCH",
+]
+env.passthrough = [
+    "OPENSSL_LIB_DIR=/usr/lib/riscv64-linux-gnu",
+    "OPENSSL_INCLUDE_DIR=/usr/include/riscv64-linux-gnu/openssl",
+    "OPENSSL_STATIC=yes"
+]
+image = "ghcr.io/cross-rs/riscv64gc-unknown-linux-gnu:edge"