Set up redirects for functions moved to module pages (backport #10692)

[mergify]

This is an automatic backport of pull request #10692 done by Mergify.
Cherry-pick of adc1d4c has failed:

On branch mergify/bp/stable/0.25/pr-10692
Your branch is up to date with 'origin/stable/0.25'.

You are currently cherry-picking commit adc1d4ccd.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	new file:   docs/api_redirects.txt

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   docs/conf.py
	both modified:   requirements-dev.txt

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/github/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

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[qiskit-bot]

Thank you for opening a new pull request.

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[coveralls]

Pull Request Test Coverage Report for Build 6027898584

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 18 unchanged lines in 3 files lost coverage.
• Overall coverage decreased (-0.009%) to 87.255%

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Files with Coverage Reduction	New Missed Lines	%
crates/qasm2/src/lex.rs	3	91.9%
qiskit/pulse/library/waveform.py	3	93.75%
crates/qasm2/src/parse.rs	12	97.13%

Totals
Change from base Build 6025720840:	-0.009%
Covered Lines:	74123
Relevant Lines:	84950

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💛 - Coveralls