CI: Resolve use of variable TRAVIS_OS_NAME

.ci.sh

@@ -33,13 +33,16 @@
 
 set -e
 
-if [[ ${TRAVIS_OS_NAME} = osx ]]; then
+if [[ ${RUNNER_OS} = macOS ]]; then
     latest_brew_python3_bin="$(ls -1d /usr/local/Cellar/python/3.*/bin | sort -n | tail -n1)"
     export PATH="${latest_brew_python3_bin}${PATH:+:}${PATH}"
     export PATH="/usr/local/opt/coreutils/libexec/gnubin${PATH:+:}${PATH}"
     export PATH="/usr/local/opt/findutils/libexec/gnubin${PATH:+:}${PATH}"
-elif [[ ${TRAVIS_OS_NAME} = linux ]]; then
+elif [[ ${RUNNER_OS} = Linux ]]; then
     export PATH="/usr/lib/llvm-15/bin:${PATH}"
+else
+    echo "Unsupported RUNNER_OS \"${RUNNER_OS}\"." >&2
+    exit 1
 fi
 
 echo "New \${PATH}:"

.github/workflows/coverage.yml

@@ -79,7 +79,6 @@ jobs:
     - name: Collect test coverage
       env:
         MODE: coverage-sh
-        TRAVIS_OS_NAME: linux
       run: |
         exec ./.ci.sh
 

.github/workflows/linux.yml

@@ -137,6 +137,5 @@ jobs:
     - name: Perform check "${{ matrix.MODE }}"
       env:
         MODE: ${{ matrix.MODE }}
-        TRAVIS_OS_NAME: linux
       run: |
         env ${{ matrix.FLAT_ENV }} ./.ci.sh

.github/workflows/macos.yml

@@ -61,6 +61,5 @@ jobs:
     - name: Perform check "${{ matrix.MODE }}"
       env:
         MODE: ${{ matrix.MODE }}
-        TRAVIS_OS_NAME: osx
       run: |
         env ${{ matrix.FLAT_ENV }} ./.ci.sh