[Merged by Bors] - chore: bump toolchain to v4.29.0-rc7

[kim-em]

This brings the new inferInstanceAs implementation.

[github-actions]

PR summary 1ea3462986

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference

---

Declarations diff

+ add_top
+ rec_bot
+ rec_coe
+ rec_top
+ stripHeaderEmoji
+ top_add
- instance : IsUniformGroup Circle := inferInstance

You can run this locally as follows

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

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

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

---

Increase in tech debt: (relative, absolute) = (6.39, 1.33)

Current number	Change	Type
10	1	maxHeartBeats modifications
8562	-151	backward.isDefEq
12	3	disabled deprecation lints
40	40	backward.inferInstanceAs

Current commit ae37be3877
Reference commit 1ea3462986

You can run this locally as

./scripts/reporting/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).

[kim-em]

These changes have already been reviewed in leanprover-community#201, and I've gone through all the files looking for anything different from that, so I'm going to put this on the queue now.

bors p=100

bors merge

[mathlib-bors]

Build failed:

• ci (staging) / Build

[kim-em]

Problem with a newly landed file. Rebasing and fixing now.

[kim-em]

bors merge

[mathlib-bors]

Pull request successfully merged into master.

Build succeeded:

• ci (staging) / Build
• ci (staging) / Lint style
• ci (staging) / Post-CI job
• ci (staging) / Post-Build Step

[JovanGerb]

@kim-em, I have noticed now that this PR makes a change in to_additive and fun_prop that makes the trace messages worse. Could you please, in the future, be transparent about this, and clearly mention such changes in the PR description? That way, we can remember to fix such things later!