ci: remove unnecessary file ci/script.sh

It only runs run_tests.sh and checks coverage, which can be replaced by
just moving the coverage check to ci/run_tests.sh.

ci/run_tests.sh

@@ -33,3 +33,9 @@ for i in "${tests[@]}"; do
 done
 
 end_tests
+
+if [[ -s "${GCOV_ERROR_FILE}" ]]; then
+  echo '=== Unexpected gcov errors: ==='
+  cat "${GCOV_ERROR_FILE}"
+  exit 1
+fi

ci/script.sh

@@ -1,12 +0,0 @@
-#!/usr/bin/env bash
-
-set -e
-set -o pipefail
-
-ci/run_tests.sh
-
-if [[ -s "${GCOV_ERROR_FILE}" ]]; then
-  echo '=== Unexpected gcov errors: ==='
-  cat "${GCOV_ERROR_FILE}"
-  exit 1
-fi