vcpkg ci: grep returns -1 when it finds nothing, use || true so that the term returns 0 (#20236)

.github/workflows/untrustedPR.yml

@@ -38,7 +38,7 @@ jobs:
           git config user.email github-actions
           git config user.name github-actions@github.com
 
-          git diff --name-status --merge-base HEAD^ HEAD --diff-filter=MAR -- '*portfile.cmake' | sed 's/[MAR]\t*//' | while read filename; do grep -q -E '(vcpkg_install_cmake|vcpkg_build_cmake|vcpkg_configure_cmake|vcpkg_fixup_cmake_targets)' "$filename" && echo " - \`$filename\`"; done > .github-pr.deprecated-cmake
+          git diff --name-status --merge-base HEAD^ HEAD --diff-filter=MAR -- '*portfile.cmake' | sed 's/[MAR]\t*//' | while read filename; do grep -q -E '(vcpkg_install_cmake|vcpkg_build_cmake|vcpkg_configure_cmake|vcpkg_fixup_cmake_targets)' "$filename" && echo " - \`$filename\`" || true; done > .github-pr.deprecated-cmake
           ./vcpkg format-manifest --all --convert-control
           git diff > .github-pr.format-manifest
           git add -u