CI: Build Linux releases using ubuntu-20.04 runner

.github/workflows/release.yml

@@ -20,7 +20,7 @@ jobs:
         name: [linux, armv7, arm64, windows, macos]
         include:
           - name: linux
-            os: ubuntu-18.04
+            os: ubuntu-20.04
             build_deps: >
               libfuse-dev
             build_flags: --features mount
@@ -28,7 +28,7 @@ jobs:
             asset_suffix: x86_64-linux.tar.gz
 
           - name: armv7
-            os: ubuntu-18.04
+            os: ubuntu-20.04
             target: armv7-unknown-linux-gnueabihf
             build_deps: >
               gcc-arm-linux-gnueabihf
@@ -40,7 +40,7 @@ jobs:
             asset_suffix: armv7-linux.tar.gz
 
           - name: arm64
-            os: ubuntu-18.04
+            os: ubuntu-20.04
             target: aarch64-unknown-linux-gnu
             build_deps: >
               gcc-aarch64-linux-gnu
@@ -113,7 +113,7 @@ jobs:
 
   deb:
     name: Debian ${{ matrix.name }}
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-20.04
     strategy:
       matrix:
         name: [linux, linux-musl, armv7, armv7-musl, arm64, arm64-musl]