builder: optimize tarfs building speed by skipping file content

[jiangliu]

The tarfs crate provides seekable reader to iterate entries in tar file, so optimize tarfs building speed by skipping file content.

Types of changes

What types of changes does your PullRequest introduce? Put an x in all the boxes that apply:

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation Update (if none of the other choices apply)

Checklist

Go over all the following points, and put an x in all the boxes that apply.

• I have updated the documentation accordingly.
• I have added tests to cover my changes.

[anolis-bot]

@jiangliu , a new test job has been submitted. Please wait in patience. The test job url: https://tone.openanolis.cn/ws/nrh4nnio/test_result/85275

[anolis-bot]

@jiangliu , The CI test is completed, please check result:

Test Case		Test Result
build rust golang image		✅ SUCCESS
compile nydusd		❌ FAIL

Sorry, your test job failed. Please get the details in the link.

[anolis-bot]

@jiangliu , the code has been updated, so a new test job has been submitted. Please wait in patience. The test job url: https://tone.openanolis.cn/ws/nrh4nnio/test_result/85278

[codecov]

Codecov Report

Merging #1376 (6b2deca) into master (be52ebd) will decrease coverage by 0.02%.
The diff coverage is 25.80%.

@@            Coverage Diff             @@
##           master    #1376      +/-   ##
==========================================
- Coverage   46.16%   46.15%   -0.02%     
==========================================
  Files         122      122              
  Lines       37913    37952      +39     
  Branches    37913    37952      +39     
==========================================
+ Hits        17503    17515      +12     
- Misses      19490    19516      +26     
- Partials      920      921       +1     

Impacted Files	Coverage Δ
builder/src/tarball.rs	62.67% <19.64%> (-2.88%)	⬇️
utils/src/reader.rs	88.57% <83.33%> (-0.50%)	⬇️

... and 2 files with indirect coverage changes

[anolis-bot]

@jiangliu , The CI test is completed, please check result:

Test Case		Test Result
build rust golang image		✅ SUCCESS
compile nydusd		✅ SUCCESS
compile ctr remote		✅ SUCCESS
compile nydus snapshotter		✅ SUCCESS
run container with rafs		✅ SUCCESS
run container with zran		✅ SUCCESS
run container with rafs and compile linux		✅ SUCCESS

Congratulations, your test job passed!

[imeoer]

LGTM