Add new image builders

[ArthurKamalov]

This PR introduces new builders that have to replace existing agent docker/k8s image builders.

Main changes (for now):

1. Ubuntu base image is used instead of the Debian.
2. To cache intermediate results and to speed up the build, we use the gha cache

Old workflows with previous version of docker images were deleted.

[github-actions[bot]]

Test Results

     29 files  ±0       29 suites  ±0   49m 34s :stopwatch: -4s 1 443 tests ±0  1 423 :heavy_check_mark: ±0    20 :zzz: ±0  0 :x: ±0  9 736 runs  ±0  9 478 :heavy_check_mark:  - 1  258 :zzz: +1  0 :x: ±0 

Results for commit 40c71853. ± Comparison against base commit 64c98caa.

:recycle: This comment has been updated with latest results.

[codecov[bot]]

Codecov Report

Merging #1161 (40c7185) into master (64c98ca) will decrease coverage by 0.03%. The diff coverage is 92.86%.

@@            Coverage Diff             @@
##           master    #1161      +/-   ##
==========================================
- Coverage   79.48%   79.45%   -0.03%     
==========================================
  Files         186      186              
  Lines       42888    42889       +1     
  Branches     4807     4807              
==========================================
- Hits        34088    34074      -14     
- Misses       7594     7602       +8     
- Partials     1206     1213       +7     

Impacted Files	Coverage Δ
scalyr_agent/config_main.py	23.35% <0.00%> (ø)
...gent/builtin_monitors/kubernetes_events_monitor.py	65.06% <100.00%> (-0.96%)	:arrow_down:
...calyr_agent/builtin_monitors/kubernetes_monitor.py	67.22% <100.00%> (ø)
scalyr_agent/monitor_utils/k8s.py	80.92% <100.00%> (-0.62%)	:arrow_down:
scalyr_agent/requests_connection.py	63.16% <100.00%> (ø)
scalyr_agent/scalyr_client.py	78.90% <100.00%> (-0.79%)	:arrow_down:
tests/smoke_tests/monitors_test/mysql_test.py	34.59% <100.00%> (ø)
tests/smoke_tests/monitors_test/postgres_test.py	33.33% <100.00%> (ø)
...s/unit/builtin_monitors/kubernetes_monitor_test.py	99.09% <100.00%> (ø)
tests/unit/monitor_utils/k8s_test.py	96.42% <100.00%> (ø)
... and 1 more

... and 4 files with indirect coverage changes