Merge pull request #82 from striezel-stash/ci-ubuntu-20.04-deprecation

ci: move Ubuntu 20.04 builds to container

Author: zajo

.github/workflows/ci.yml

@@ -33,14 +33,17 @@ jobs:
             container: ubuntu:18.04
           - toolset: gcc-8
             cxxstd: "11,14,17,2a"
-            os: ubuntu-20.04
+            os: ubuntu-latest
+            container: ubuntu:20.04
             install: g++-8
           - toolset: gcc-9
             cxxstd: "11,14,17,2a"
-            os: ubuntu-20.04
+            os: ubuntu-latest
+            container: ubuntu:20.04
           - toolset: gcc-10
             cxxstd: "11,14,17,2a"
-            os: ubuntu-20.04
+            os: ubuntu-latest
+            container: ubuntu:20.04
             install: g++-10
           - toolset: gcc-11
             cxxstd: "11,14,17,20"
@@ -80,35 +83,45 @@ jobs:
           - toolset: clang
             compiler: clang++-6.0
             cxxstd: "11,14,17"
-            os: ubuntu-20.04
+            os: ubuntu-latest
+            container: ubuntu:20.04
             install: clang-6.0
           - toolset: clang
             compiler: clang++-7
             cxxstd: "11,14,17"
-            os: ubuntu-20.04
+            os: ubuntu-latest
+            container: ubuntu:20.04
             install: clang-7
           - toolset: clang
             compiler: clang++-8
             cxxstd: "11,14,17"
-            os: ubuntu-20.04
+            os: ubuntu-latest
+            container: ubuntu:20.04
             install: clang-8
           - toolset: clang
             compiler: clang++-9
             cxxstd: "11,14,17"
-            os: ubuntu-20.04
+            os: ubuntu-latest
+            container: ubuntu:20.04
             install: clang-9
           - toolset: clang
             compiler: clang++-10
             cxxstd: "11,14,17,2a"
-            os: ubuntu-20.04
+            os: ubuntu-latest
+            container: ubuntu:20.04
+            install: clang-10
           - toolset: clang
             compiler: clang++-11
             cxxstd: "11,14,17,2a"
-            os: ubuntu-20.04
+            os: ubuntu-latest
+            container: ubuntu:20.04
+            install: clang-11
           - toolset: clang
             compiler: clang++-12
             cxxstd: "11,14,17,20"
-            os: ubuntu-20.04
+            os: ubuntu-latest
+            container: ubuntu:20.04
+            install: clang-12
           - toolset: clang
             compiler: clang++-13
             cxxstd: "11,14,17,20,2b"