ci: Fix and update the configuration for Travis CI and AppVeyor CI

.appveyor.yml

@@ -1,9 +1,9 @@
-version: 1.6.x-{build}
+version: 1.8.x-{build}
 
 branches:
   except:
     - /libpng[0-1][0-8]/
-    - /v[0-1][.][0-7][.][0-9]+/
+    - /v[0-1][.][0-8][.][0-9]+/
 
 image:
   - Visual Studio 2022
@@ -67,7 +67,7 @@ before_build:
   - 'set CI_CMAKE_BUILD_FLAGS=-j2'
   - 'set CI_CTEST_FLAGS=-j2'
   - 'set CI_MAKE_FLAGS=-j2'
-  - 'set CI_MAKEFILES=scripts/makefile.gcc scripts/makefile.msys scripts/makefile.std'
+  - 'set CI_MAKEFILES=scripts/makefile.gcc scripts/makefile.std'
 
 build_script:
   - 'if "%TOOLCHAIN%"=="vstudio" C:\msys64\usr\bin\bash.exe -l "%APPVEYOR_BUILD_FOLDER%\ci\ci_verify_cmake.sh"'
@@ -77,5 +77,5 @@ build_script:
   - 'if "%TOOLCHAIN%"=="msys2" if "%AUTOMATION%"=="makefiles" C:\msys64\usr\bin\bash.exe -l "%APPVEYOR_BUILD_FOLDER%\ci\ci_verify_makefiles.sh"'
 
 cache:
-  - C:\tools\vcpkg\installed
-  - C:\msys64\var\cache\pacman
+  - 'C:\tools\vcpkg\installed'
+  - 'C:\msys64\var\cache\pacman'

.travis.yml

@@ -1,7 +1,7 @@
 branches:
   except:
     - /libpng[0-1][0-8]/
-    - /v[0-1][.][0-7][.][0-9]+/
+    - /v[0-1][.][0-8][.][0-9]+/
 
 language: c