Fix unauthorized error with buildx needing multiple credentials

[eocantu]

This addresses a 401 Unauthorized error when building for multi-platform and multiple credentials are needed for different registries. For example, if the image name is registry-one.org/library/example and the base (FROM) image is in another registry (e.g. registry-two.org), two credentials are needed: one for each registry.

I believe this would also fix #1583 .

[codecov]

Codecov Report

Merging #1693 (8be2efc) into master (6eeb78a) will increase coverage by 0.15%.
The diff coverage is 89.65%.

❗ Current head 8be2efc differs from pull request most recent head dba3339. Consider uploading reports for the commit dba3339 to get more accurate results

@@             Coverage Diff              @@
##             master    #1693      +/-   ##
============================================
+ Coverage     64.01%   64.17%   +0.15%     
- Complexity     2198     2216      +18     
============================================
  Files           171      172       +1     
  Lines          9985    10040      +55     
  Branches       1371     1380       +9     
============================================
+ Hits           6392     6443      +51     
- Misses         3058     3061       +3     
- Partials        535      536       +1     

Impacted Files	Coverage Δ
...io/fabric8/maven/docker/service/BuildXService.java	74.14% <ø> (-0.69%)	⬇️
...c/main/java/io/fabric8/maven/docker/BuildMojo.java	51.20% <82.85%> (+11.63%)	⬆️
...ava/io/fabric8/maven/docker/access/AuthConfig.java	100.00% <100.00%> (ø)
...io/fabric8/maven/docker/access/AuthConfigList.java	100.00% <100.00%> (ø)
.../fabric8/maven/docker/service/RegistryService.java	80.72% <100.00%> (ø)

... and 1 file with indirect coverage changes

[sonarqubecloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
2 Code Smells

91.5% Coverage
0.0% Duplication