chore: update package template engines version

[jonchurch]

Which problem is this PR solving?

• The packages template lists Node.js >=8.0.0 under supported engines in the default package.json. OTLP JS lists v8.5.0 as the min supported Node.js version. New packages that copy the template may fail to update the current default.

Short description of the changes

• Bump the engines field in package.json to >=8.5.0 to be in line with Node.js version support of the project.

closes #2318

[linux-foundation-easycla]

The committers are authorized under a signed CLA.

• ✅ Jonathan Church (aa4fa3b)

[codecov]

Codecov Report

Merging #2319 (d658b3b) into main (4b3425d) will decrease coverage by 0.13%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #2319      +/-   ##
==========================================
- Coverage   92.77%   92.63%   -0.14%     
==========================================
  Files         145      142       -3     
  Lines        5216     5091     -125     
  Branches     1068     1047      -21     
==========================================
- Hits         4839     4716     -123     
+ Misses        377      375       -2     

Impacted Files	Coverage Δ
...ontext-async-hooks/src/AsyncHooksContextManager.ts
...sync-hooks/src/AbstractAsyncHooksContextManager.ts
...async-hooks/src/AsyncLocalStorageContextManager.ts