libsecret: upgrade 0.21.6 -> 0.21.7

libsecret: upgrade 0.21.6 -> 0.21.7

Changelog:
- docs: Fix return comment of secret_value_get_text
- bash-completion: Fix man section number in secret-tool completion file
- bash-completion: Integrate external extended bash-completion script
- bash-completion: Require minimal version for bash-completion
- meson: Use newlines for build options

Signed-off-by: Gyorgy Sarvari <skandigraun@gmail.com>
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>