rtm-api(build): use a minimum version of @slack/web-api@7.3.4

[zimeg]

Summary

This PR sets the minimum version of @slack/web-api to 7.3.4 to address CVE-2024-39338. Follows #1878.

Requirements

• I've read and understood the Contributing Guidelines and have done my best effort to follow them.
• I've read and agree to the Code of Conduct.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 89.85%. Comparing base (7910bc9) to head (82812bc).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1887   +/-   ##
=======================================
  Coverage   89.85%   89.85%           
=======================================
  Files          34       34           
  Lines        7648     7648           
  Branches      374      374           
=======================================
  Hits         6872     6872           
  Misses        764      764           
  Partials       12       12           

Flag	Coverage Δ
cli-hooks	94.94% <ø> (ø)
cli-test	94.77% <ø> (ø)
oauth	76.53% <ø> (ø)
socket-mode	59.59% <ø> (ø)
web-api	96.57% <ø> (ø)
webhook	95.27% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.