CI: bump esp-idf + fixup 5.2.7

[petermm]

Minor snag with 5.2.7 crashing on the idf.py size command for some reason unrelated to atomvm, so minor cleanup there.

These changes are made under both the "Apache 2.0" and the "GNU Lesser General
Public License 2.1 or later" license terms (dual license).

SPDX-License-Identifier: Apache-2.0 OR LGPL-2.1-or-later

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