fix(ci): make Prettier workflow pass on develop (#4941)

* style(alerts): prettier-format alert_matrix.sh

Add the space in '2> /dev/null' that prettier-plugin-sh expects. This
was in the original #4901 code and tripped the Prettier workflow on
develop after merge (the workflow auto-formats and then can't push to
the protected branch, so the run fails).

* ci(prettier): ignore package-lock.json

package-lock.json is machine-generated by npm; Prettier reformatting it
conflicts with npm's own output and causes the Prettier auto-commit
workflow to try (and fail) to push lockfile churn to protected develop.
Ignoring it lets the workflow find nothing to change and pass.

.prettierignore

@@ -1,3 +1,7 @@
 # Prettier auto-commit runs with GITHUB_TOKEN (GitHub App).
 # GitHub blocks that token from creating/updating anything under .github/workflows.
 .github/workflows/**
+
+# Machine-generated by npm; its format is owned by npm, not Prettier.
+# Prettier reformatting it fights npm and makes the auto-commit run fail.
+package-lock.json

lgsm/modules/alert_matrix.sh

@@ -60,7 +60,7 @@ matrixsend=$(curl --connect-timeout 10 -sSL -X PUT \
 	"${matrixurl}")
 exitcode=$?
 
-matrixeventid="$(echo "${matrixsend}" | jq -r '.event_id // empty' 2>/dev/null)"
+matrixeventid="$(echo "${matrixsend}" | jq -r '.event_id // empty' 2> /dev/null)"
 if [ "${exitcode}" -eq 0 ] && [ -n "${matrixeventid}" ]; then
 	fn_print_ok_nl "Sending Matrix alert"
 	fn_script_log_pass "Sending Matrix alert"