apacheGH-40833: [Docs][Release] Make explicit in the documentation th…

…at verifying binaries is not required in order to case a vote (apache#40834)

### Rationale for this change

Based on the discussion on https://lists.apache.org/thread/ogp9dthp124oq0fmvlyzvjorjsyom03v making clear that binaries verification are not required in order to cast a positive vote for the release.

### What changes are included in this PR?

Document the required process

### Are these changes tested?

preview-docs job on archery will be run

### Are there any user-facing changes?

No
* GitHub Issue: apache#40833

Authored-by: Raúl Cumplido <raulcumplido@gmail.com>
Signed-off-by: Raúl Cumplido <raulcumplido@gmail.com>

docs/source/developers/release_verification.rst

@@ -55,7 +55,7 @@ and test the result on their own platform in order to cast a +1 vote.
 
    # this will create and automatically clean up a temporary directory for the verification environment and will run the source verification
    TEST_DEFAULT=0 TEST_SOURCE=1 verify-release-candidate.sh $VERSION $RC_NUM
-
+   
    # to verify only certain implementations use the TEST_DEFAULT=0 and TEST_* variables
    # here are a couple of examples, but see the source code for the available options
    TEST_DEFAULT=0 TEST_CPP=1 verify-release-candidate.sh $VERSION $RC_NUM  # only C++ tests