[Misc] Fix quoting issue in build_deploy.sh

Description

PR !1157 (merged) causes an issue where multiple flags destined for build_rpm.sh are merged into a single argument, causing the script to fail.

The quoting caused the flags -install-srpms --skip-unit-tests --enable-ccache to be presented as a single argument, rather than being passed as individual CLI args.

Example error output:

BUILDING RPMS


Invalid argument:  --install-srpms --skip-unit-tests --enable-ccache
--use-internal-repos

Usage: /./shared/CTA/continuousintegration/build/build_rpm.sh [options]
--build-dir <build-dir> --srpm-dir <srpm-directory> --scheduler-type
<scheduler-type> --cta-version <cta-version> --vcs-version <vcs-version>
--xrootd-ssi-version <xrootd-ssi-version>

This PR ensures that:

• build_rpm.sh receives the correct flags
• shellcheck does not complain about the line

Checklist

• Documentation reflects the changes made.
• Merge Request title is clear, concise, and suitable as a changelog entry. See our contributing docs