Fix docs typo in qk_obsterm_str

[Cryoris]

Summary

We missed a print -> str rename in the docs. The function is now called qk_obsterm_str, not qk_obsterm_print anymore.

[qiskit-bot]

One or more of the following people are relevant to this code:

• @Qiskit/terra-core

[coveralls]

Pull Request Test Coverage Report for Build 13658437474

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
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• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 7 unchanged lines in 2 files lost coverage.
• Overall coverage decreased (-0.005%) to 87.113%

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Files with Coverage Reduction	New Missed Lines	%
crates/accelerate/src/unitary_synthesis.rs	1	94.39%
crates/qasm2/src/lex.rs	6	91.73%

Totals
Change from base Build 13655794837:	-0.005%
Covered Lines:	76426
Relevant Lines:	87732

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💛 - Coveralls