Spin session on empty wait (backport #233)

[mergify[bot]]

This is an automatic backport of pull request #233 done by Mergify. Cherry-pick of 7670ac9b9ffd4cdb5837e6fd4a7f525f9c043cc7 has failed:

On branch mergify/bp/foxy/pr-233
Your branch is up to date with 'origin/foxy'.

You are currently cherry-picking commit 7670ac9.
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Unmerged paths:
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    both modified:   rmw_microxrcedds_c/src/rmw_wait.c

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To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/github/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

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[github-actions[bot]]

Static memory analysis

Default configuration

MTU: 512 B Input buffer size: 2048 B Input history: 4 Output buffer size: 2048 B Output history: 4

Entity	Qty	Size per unit
Context	2	5616 B
Topic	8	56 B
Service	4	248 B
Client	4	248 B
Subscription	4	272 B
Publisher	4	280 B
Node	4	208 B
Static input buffer	8	2136 B
Init options	6	64 B
Wait sets	4	56 B
Guard Condition	4	64 B

TOTAL: 34436 B

[codecov-commenter]

Codecov Report

Merging #239 (619892c) into foxy (13efbb8) will increase coverage by 0.14%. The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             foxy     #239      +/-   ##
==========================================
+ Coverage   49.97%   50.11%   +0.14%     
==========================================
  Files          41       41              
  Lines        1673     1678       +5     
  Branches      477      478       +1     
==========================================
+ Hits          836      841       +5     
  Misses        613      613              
  Partials      224      224              

Impacted Files	Coverage Δ
rmw_microxrcedds_c/src/rmw_wait.c	86.76% <100.00%> (+1.05%)	:arrow_up:

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