docs: submitting-patches: clarify that signers may use their discretion on tags

Tags are really appreciated by maintainers in general, since it means
someone is willing to put their name on a commit, be it as a reviewer,
tester, etc.

However, signers (i.e. submitters carrying tags from previous versions
and maintainers applying patches) may need to take or drop tags, on a
case-by-case basis, for different reasons.

Yet this is not explicitly spelled out in the documentation, thus there
may be instances [1] where contributors may feel unwelcome.

Thus, to clarify, state this clearly.

Link: https://lore.kernel.org/rust-for-linux/CAEg-Je-h4NitWb2ErFGCOqt0KQfXuyKWLhpnNHCdRzZdxi018Q@mail.gmail.com/ [1]
Suggested-by: Dan Williams <[email protected]>
Acked-by: Shuah Khan <[email protected]>
Acked-by: Dan Williams <[email protected]>
Signed-off-by: Miguel Ojeda <[email protected]>
Acked-by: Greg Kroah-Hartman <[email protected]>
Acked-by: Krzysztof Kozlowski <[email protected]>
Signed-off-by: Jonathan Corbet <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

Documentation/process/submitting-patches.rst

@@ -614,6 +614,10 @@ process nor the requirement to Cc: [email protected] on all stable
 patch candidates. For more information, please read
 Documentation/process/stable-kernel-rules.rst.
 
+Finally, while providing tags is welcome and typically very appreciated, please
+note that signers (i.e. submitters and maintainers) may use their discretion in
+applying offered tags.
+
 .. _the_canonical_patch_format:
 
 The canonical patch format