Meta: Tweak shell_include.sh

* `chmod -x` as it's for sourcing, not for executing
* Remove run line, for the same reason
* Rename it from .shell_include.sh to shell_include.sh, since e.g.
  `rg` doesn't search in hidden files by default

No behavior change.

Meta/shell_include.sh

@@ -0,0 +1,53 @@
+# shellcheck shell=bash
+# shellcheck disable=SC2034
+# SC2034: "Variable appears unused. Verify it or export it."
+#         Those are intentional here, as the file is meant to be included elsewhere.
+
+# NOTE: If using another privilege escalation binary make sure it is configured or has the appropiate flag
+#       to keep the current environment variables in the launched process (in sudo's case this is achieved
+#       through the -E flag described in sudo(8).
+SUDO="sudo -E"
+
+if [ "$(uname -s)" = "SerenityOS" ]; then
+    SUDO="pls -E"
+fi
+
+die() {
+    echo "die: $*"
+    exit 1
+}
+
+find_executable() {
+  paths=("/usr/sbin" "/sbin")
+
+  if [ "$(uname -s)" = "Darwin" ]; then
+    if [ -n "${HOMEBREW_PREFIX}" ]; then
+      paths+=("${HOMEBREW_PREFIX}/opt/e2fsprogs/bin" "${HOMEBREW_PREFIX}/opt/e2fsprogs/sbin")
+    elif command -v brew > /dev/null 2>&1; then
+      if prefix=$(brew --prefix e2fsprogs 2>/dev/null); then
+        paths+=("${prefix}/bin" "${prefix}/sbin")
+      fi
+    fi
+  fi
+
+  executable="${1}"
+
+  # Prefer tools from PATH over fallback paths
+  if command -v "${executable}"; then
+    return 0
+  fi
+
+  for path in "${paths[@]}"; do
+    if command -v "${path}/${executable}"; then
+      return 0
+    fi
+  done
+
+  # We return the executable's name back to provide meaningful messages on future failure
+  echo "${executable}"
+}
+
+FUSE2FS_PATH="$(find_executable fuse2fs)"
+RESIZE2FS_PATH="$(find_executable resize2fs)"
+E2FSCK_PATH="$(find_executable e2fsck)"
+MKE2FS_PATH="$(find_executable mke2fs)"