Fix version number in docs

[epassaro]

Description
Solves #1391

Motivation and context

I was porting the carsus doc to GA and suddenly realized what's happening. The checkout action from GA by default just fetches the latest commit, and the "old" astropy_helper version solver uses the number of commits to calculate the dev version. Using fetch-depth: 0 in the step args solves this issue.

How has this been tested?

• Testing pipeline.
• Other.

Tested in carsus documentation.

Examples

Type of change

• Bug fix.
• New feature.
• Breaking change.
• None of the above.

Checklist

• My change requires a change to the documentation.
  • I have updated the documentation accordingly.
  • (optional) I have built the documentation on my fork following the instructions.
• I have assigned and requested two reviewers for this pull request.

[codecov]

Codecov Report

Merging #1540 (10ef991) into master (a15551c) will not change coverage.
The diff coverage is n/a.

❗ Current head 10ef991 differs from pull request most recent head 024899e. Consider uploading reports for the commit 024899e to get more accurate results

@@           Coverage Diff           @@
##           master    #1540   +/-   ##
=======================================
  Coverage   69.06%   69.06%           
=======================================
  Files          68       68           
  Lines        6106     6106           
=======================================
  Hits         4217     4217           
  Misses       1889     1889           

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update a15551c...024899e. Read the comment docs.