feat(workflows): automatically assign reviewers

[grunweg]

Once per day, automatically assign all proposed reviewers from the automatic assignment algorithm.
These are initial suggestions; users are free to manually assign to somebody else (or to un-assign themselves; after a day, the algorithm will randomly choose a user again.)

To work around variable quoting issues, we follow a slightly roundabout approach: instead of parsing the json file using a shell script and calling the github API from bash in a loop, we use Python to parse the file, generate a shell script with the desired APIi calls, and execute that script instead.
(This has the advantage of making the output easily auditable; future rewrites are also welcome.)

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See the github documentation for the assignment syntax used.

[github-actions]

PR summary 8635ef05f0

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference

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Declarations diff

+ call(number:

You can run this locally as follows

## summary with just the declaration names:
./scripts/declarations_diff.sh <optional_commit>

## more verbose report:
./scripts/declarations_diff.sh long <optional_commit>

The doc-module for script/declarations_diff.sh contains some details about this script.

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No changes to technical debt.

You can run this locally as

./scripts/technical-debt-metrics.sh pr_summary

• The relative value is the weighted sum of the differences with weight given by the inverse of the current value of the statistic.
• The absolute value is the relative value divided by the total sum of the inverses of the current values (i.e. the weighted average of the differences).

[grunweg]

Duplicate of #26109; this has fulfilled its purpose.