Prevent dependabot from opening issues about test or example data

[UebelAndre]

Over the weekend it seems someone enabled dependabot and it now suggest changes that are likely to generate a ton of noise and do not have a meaningful impact to users. We should make sure we don't get walls of similar issues in the future.

New issues:

• Bump regex from 1.5.4 to 1.5.6 in /examples/crate_universe/cargo_aliases #1389

• Bump regex from 1.5.4 to 1.5.6 in /examples/crate_universe/multi_package/pkg_a #1388

• Bump tokio from 1.13.0 to 1.16.1 in /examples/crate_universe/multi_package/pkg_a #1386

• Bump tokio from 1.12.0 to 1.13.1 in /examples/crate_universe/cargo_local #1385

• Bump crossbeam-utils from 0.8.5 to 0.8.8 in /examples/crate_universe/multi_package/pkg_a #1383

Of all the new issues, these are the only ones that might be remotely beneficial as it's complaining about real dependencies users might consume.

• Bump regex from 1.5.4 to 1.5.6 in /bindgen/raze #1387
• Bump crossbeam-deque from 0.7.3 to 0.7.4 in /proto/raze #1382

[UebelAndre]

cc @hlopko @scentini

Figured this is something only Googlers would have insight into.

[scentini]

It looks like I don't have sufficient permissions to make such changes to this repository, reassigning to @hlopko.

[hlopko]

I've just disabled the dependabot completely, but I'm tempted to enable it back again once dependabot/dependabot-core#4364 is resolved (so we can ignore /examples since those warnings are not highly important if you ask me, but introduce a lot of noise)