Switch to ubuntu-latest for Linux builds

Author: petergeneric

.github/workflows/build.yml

@@ -16,13 +16,13 @@ jobs:
       fail-fast: false
       matrix:
         job:
-          - { os: ubuntu-20.04, target: arm-unknown-linux-gnueabihf , use-cross: true }
-          - { os: ubuntu-20.04, target: arm-unknown-linux-musleabihf, use-cross: true }
-          - { os: ubuntu-20.04, target: aarch64-unknown-linux-gnu   , use-cross: true }
-          - { os: ubuntu-20.04, target: i686-unknown-linux-gnu      , use-cross: true }
-          - { os: ubuntu-20.04, target: i686-unknown-linux-musl     , use-cross: true }
-          - { os: ubuntu-20.04, target: x86_64-unknown-linux-gnu    , use-cross: true }
-          - { os: ubuntu-20.04, target: x86_64-unknown-linux-musl   , use-cross: true }
+          - { os: ubuntu-latest, target: arm-unknown-linux-gnueabihf , use-cross: true }
+          - { os: ubuntu-latest, target: arm-unknown-linux-musleabihf, use-cross: true }
+          - { os: ubuntu-latest, target: aarch64-unknown-linux-gnu   , use-cross: true }
+          - { os: ubuntu-latest, target: i686-unknown-linux-gnu      , use-cross: true }
+          - { os: ubuntu-latest, target: i686-unknown-linux-musl     , use-cross: true }
+          - { os: ubuntu-latest, target: x86_64-unknown-linux-gnu    , use-cross: true }
+          - { os: ubuntu-latest, target: x86_64-unknown-linux-musl   , use-cross: true }
           - { os: macos-latest, target: x86_64-apple-darwin         }
           - { os: macos-latest, target: aarch64-apple-darwin        }
     steps: