ci: do not use "latest" images

Use stable images for reproducibility. Well, reproducible as long as
github does not change the images, which they do...

.github/workflows/ci.yml

@@ -14,7 +14,7 @@ env:
 jobs:
   test-linux:
     name: Test ${{matrix.build}}
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
 
     steps:
       - name: Install openssl x86 and 32 support for gcc
@@ -49,7 +49,7 @@ jobs:
 
   test-windows:
     name: Test ${{matrix.build}}
-    runs-on: windows-latest
+    runs-on: windows-2022
 
     steps:
       - uses: actions/checkout@v3
@@ -102,7 +102,7 @@ jobs:
 
   clippy:
     name: Clippy
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     steps:
       - uses: actions/checkout@v3
       - uses: dtolnay/rust-toolchain@stable
@@ -112,7 +112,7 @@ jobs:
 
   rustmt:
     name: Rustfmt
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     steps:
       - uses: actions/checkout@v3
       - uses: dtolnay/rust-toolchain@stable
@@ -122,14 +122,14 @@ jobs:
 
   deny:
     name: Deny
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     steps:
       - uses: actions/checkout@v3
       - uses: EmbarkStudios/cargo-deny-action@v1
 
   coverage:
     name: Coverage
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     env:
       CARGO_TERM_COLOR: always
     steps:
@@ -150,7 +150,7 @@ jobs:
 
   msrv:
     name: Rust 1.62.0
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     steps:
       - uses: actions/checkout@v3
       - uses: dtolnay/[email protected]