[Silabs] Do not call nvm3_repack() from the FreeRTOS idle hook

[selissia]

The NVM3 lock was changed in this PR to use semaphores. Because of this we are removing the call nvm3_repack(), a potentially blocking function, from the FreeRTOS idle hook.

Additional minor changes unrelated to the above:

• Remove conditional inclusion of the bootloader Application Properties structure in the application image, SL_CATALOG_GECKO_BOOTLOADER_INTERFACE_PRESENT is always set in Silabs' matter_support submodule.
• Update README files with bootloader info

[github-actions]

PR #25697: Size comparison from 346a817 to 6e881bc

Full report (1 build for cc32xx)

platform	target	config	section	346a817	6e881bc	change	% change
cc32xx	lock	CC3235SF_LAUNCHXL		0	0	0	0.0
			(read only)	645489	645489	0	0.0
			(read/write)	203848	203848	0	0.0
			.ARM.attributes	44	44	0	0.0
			.ARM.exidx	8	8	0	0.0
			.bss	197248	197248	0	0.0
			.comment	194	194	0	0.0
			.data	1480	1480	0	0.0
			.debug_abbrev	930293	930293	0	0.0
			.debug_aranges	87384	87384	0	0.0
			.debug_frame	300248	300248	0	0.0
			.debug_info	20245969	20245969	0	0.0
			.debug_line	2660979	2660979	0	0.0
			.debug_loc	2804909	2804909	0	0.0
			.debug_ranges	283168	283168	0	0.0
			.debug_str	3026947	3026947	0	0.0
			.ramVecs	780	780	0	0.0
			.resetVecs	64	64	0	0.0
			.rodata	106009	106009	0	0.0
			.shstrtab	232	232	0	0.0
			.stab	204	204	0	0.0
			.stabstr	441	441	0	0.0
			.stack	2048	2048	0	0.0
			.strtab	380271	380271	0	0.0
			.symtab	257312	257312	0	0.0
			.text	537360	537360	0	0.0