fix(ci): unset SODIUM_USE_PKG_CONFIG before cargo builds on all platforms

The libsodium-sys-stable build.rs panics if both SODIUM_LIB_DIR and
SODIUM_USE_PKG_CONFIG are set simultaneously. The runner infrastructure
at 172.0.0.29 has SODIUM_USE_PKG_CONFIG in its container environment
(not traceable to any workflow file or Docker image ENV layer), which
conflicts with the SODIUM_LIB_DIR approach used for cross-compilation.

Explicitly unset SODIUM_USE_PKG_CONFIG in the shell before npm/cargo
runs on all three platforms (linux-amd64, windows-amd64, linux-arm64)
in both release-beta.yml and auto-tag.yml. This is a defensive no-op
when the variable is absent, and a clean fix when it is present.

.gitea/workflows/release-beta.yml

@@ -226,6 +226,7 @@ jobs:
           APPIMAGE_EXTRACT_AND_RUN: "1"
           SODIUM_LIB_DIR: /usr/lib/x86_64-linux-gnu
         run: |
+          unset SODIUM_USE_PKG_CONFIG
           npm ci --legacy-peer-deps
           CI=true npx tauri build --target x86_64-unknown-linux-gnu
       - name: Upload artifacts
@@ -321,6 +322,7 @@ jobs:
           SODIUM_LIB_DIR: /usr/x86_64-w64-mingw32/lib
           SODIUM_STATIC: "1"
         run: |
+          unset SODIUM_USE_PKG_CONFIG
           npm ci --legacy-peer-deps
           CI=true npx tauri build --target x86_64-pc-windows-gnu
       - name: Upload artifacts
@@ -496,6 +498,7 @@ jobs:
           APPIMAGE_EXTRACT_AND_RUN: "1"
           SODIUM_LIB_DIR: /usr/lib/aarch64-linux-gnu
         run: |
+          unset SODIUM_USE_PKG_CONFIG
           npm ci --legacy-peer-deps
           CI=true npx tauri build --target aarch64-unknown-linux-gnu --bundles deb,rpm
       - name: Upload artifacts