Merge topic 'file-strings-encoding'

5b30ec28 file: Add ENCODING option to file(STRINGS) command (#10519)
ffa373e7 file: Refactor internal implementation of file(STRINGS)
Merge topic 'CheckIncludeFiles-main-prototype'

bf89f910 CheckIncludeFiles: Use modern C declaration for 'main' (#15058)
Merge topic 'doc-add_custom_command'

5bf1c5cc Help: Document add_custom_command PRE_BUILD/PRE_LINK for exe/lib only (#15059)
2a58c872 Help: Revise and format 'add_custom_command' docs
cb88742d Help: Remove stray content from 'add_custom_command' docs
Merge topic 'fix_value_not_used'

2cac483e Fix used value warning.
Merge topic 'ExternalData-drop-security-disclaimer'

f2ccc14b ExternalData: Drop 'not security software' disclaimer (#15060)
Merge branch 'master' into next
Help: Add notes for topic 'vs-special-source-file-properties'
Merge topic 'vs-special-source-file-properties' into next

770bd58a Help: Add notes for topic 'vs-special-source-file-properties'