fix(v1/remote): return an error if both auth and keychain are set

[estroz]

Fixes #1332

ping @imjasonh

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[jonjohnsonjr]

I haven't verified myself but I'm a little worried about how this might interact with the crane and gcrane packages, which use a keychain my default. This might break callers who supply WithAuth?

[estroz]

@jonjohnsonjr I'll investigate and update this PR if I find a reasonable fix.

[estroz]

From what I can see there is no way a caller that passes a crane.WithAuth and crane.WithAuthFromKeychain, either explicitly or implicitly via makeOptions, can get this error. Both options override the default keychain option. Effectively, the behavior in remote this PR corrects was already enforced by crane/gcrane.

[codecov-commenter]

Codecov Report

Merging #1334 (4e03e69) into main (efc62d8) will decrease coverage by 0.02%.
The diff coverage is 50.00%.

@@            Coverage Diff             @@
##             main    #1334      +/-   ##
==========================================
- Coverage   74.07%   74.04%   -0.03%     
==========================================
  Files         112      112              
  Lines        8385     8391       +6     
==========================================
+ Hits         6211     6213       +2     
- Misses       1570     1574       +4     
  Partials      604      604              

Impacted Files	Coverage Δ
pkg/v1/remote/options.go	71.81% <50.00%> (-2.23%)	⬇️

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[jonjohnsonjr]

Thanks!