[HUDI-599] Update release guide & release scripts due to the change of scala 2.12 build

[leesf]

Brief change log

update release scripts due to #1293

Verify this pull request

run ./deploy_staging_jars.sh

Committer checklist

• Has a corresponding JIRA in PR title & commit

• Commit message is descriptive of the change

• CI is green

• Necessary doc changes done or have another open PR

• For large changes, please consider breaking it into sub-tasks under an umbrella JIRA.

[yanghua]

LGTM thanks @leesf

[codecov-io]

Codecov Report

Merging #1364 into master will decrease coverage by 0.01%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##             master    #1364      +/-   ##
============================================
- Coverage     67.09%   67.08%   -0.02%     
  Complexity      223      223              
============================================
  Files           333      333              
  Lines         16207    16207              
  Branches       1657     1657              
============================================
- Hits          10874    10872       -2     
- Misses         4597     4598       +1     
- Partials        736      737       +1

Impacted Files	Coverage Δ	Complexity Δ
...i/utilities/deltastreamer/HoodieDeltaStreamer.java	79.79% <0%> (-1.02%)	8% <0%> (ø)
...che/hudi/common/util/BufferedRandomAccessFile.java	54.38% <0%> (-0.88%)	0% <0%> (ø)
...a/org/apache/hudi/common/util/collection/Pair.java	76% <0%> (+4%)	0% <0%> (ø)	⬇️

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