Migrating to GitHub Actions from CircleCI

[chayim]

This PR removes CircleCI and runs our actions on GitHub (hence the failing CI check). As part of this PR, maven snapshots are split out, to run upon a successful merge (and tests) against an integration branch such as master, or a versioned branch (eg 4.0).

These rules only take effect, once merged into the appropriate branch.

[codecov-commenter]

Codecov Report

Merging #2975 (0244b64) into master (3c18734) will decrease coverage by 0.10%.
The diff coverage is n/a.

❗ Current head 0244b64 differs from pull request most recent head ae27a10. Consider uploading reports for the commit ae27a10 to get more accurate results

@@             Coverage Diff              @@
##             master    #2975      +/-   ##
============================================
- Coverage     53.56%   53.45%   -0.11%     
+ Complexity     3332     3330       -2     
============================================
  Files           216      216              
  Lines         13298    13298              
  Branches        774      774              
============================================
- Hits           7123     7109      -14     
- Misses         5927     5942      +15     
+ Partials        248      247       -1     

Impacted Files	Coverage Δ
...ava/redis/clients/jedis/params/FailoverParams.java	89.47% <0.00%> (-10.53%)	⬇️
...in/java/redis/clients/jedis/JedisSentinelPool.java	65.89% <0.00%> (-5.79%)	⬇️
...rc/main/java/redis/clients/jedis/JedisFactory.java	66.32% <0.00%> (-2.05%)	⬇️
src/main/java/redis/clients/jedis/Jedis.java	84.92% <0.00%> (-0.10%)	⬇️
...redis/clients/jedis/DefaultJedisSocketFactory.java	96.05% <0.00%> (+2.63%)	⬆️

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