lint: add bash shebang

.github/scripts/integration_test_runner.sh

@@ -1,3 +1,5 @@
+#!/usr/bin/env bash
+
 # setup hardhat for compilation tests
 pushd tests/e2e/compilation/test_data/test_node_modules/
 npm install hardhat

.github/scripts/tool_test_runner.sh

@@ -1,3 +1,5 @@
+#!/usr/bin/env bash
+
 npm install --global ganache
 # used to pass --cov=$path and --cov-append to pytest
 pytest $1 tests/tools/read-storage/test_read_storage.py

.github/scripts/unit_test_runner.sh

@@ -1,3 +1,5 @@
+#!/usr/bin/env bash
+
 # used to pass --cov=$path and --cov-append to pytest
 pytest $1 tests/unit/
 if [ "$1" != "" ]; then