Update Juju agents (patch) (#287)

This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
| [juju/juju](https://redirect.github.com/juju/juju) | patch | `3.4.3`
-> `3.4.5` |
| [juju/juju](https://redirect.github.com/juju/juju) | patch | `2.9.49`
-> `2.9.50` |

---

### Release Notes

<details>
<summary>juju/juju (juju/juju)</summary>

###
[`v3.4.5`](https://redirect.github.com/juju/juju/releases/tag/v3.4.5):
Juju 3.4.5

[Compare
Source](https://redirect.github.com/juju/juju/compare/v3.4.4...v3.4.5)

##### The Juju team is proud to release Juju 3.4.5!

This is a point release to the stable 3.4 series of Juju.

Checkout the [Juju 3.4.5 Release
Notes](https://discourse.charmhub.io/t/roadmap-releases/5064)

###
[`v3.4.4`](https://redirect.github.com/juju/juju/releases/tag/v3.4.4):
Juju 3.4.4

[Compare
Source](https://redirect.github.com/juju/juju/compare/v3.4.3...v3.4.4)

##### The Juju team is proud to release Juju 3.4.4!

This is a point release to the stable 3.4 series of Juju.

Checkout the [Juju 3.4.4 Release
Notes](https://discourse.charmhub.io/t/roadmap-releases/5064)

</details>

---

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---

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.github/workflows/ci.yaml

@@ -73,18 +73,18 @@ jobs:
       fail-fast: false
       matrix:
         juju:
-          - agent: 2.9.49  # renovate: juju-agent-pin-minor
+          - agent: 2.9.50  # renovate: juju-agent-pin-minor
             libjuju: ^2
             allure_on_amd64: false
-          - agent: 3.4.3  # renovate: juju-agent-pin-minor
+          - agent: 3.4.5  # renovate: juju-agent-pin-minor
             allure_on_amd64: true
           - snap_channel: 3.6/beta
             allure_on_amd64: false
         architecture:
           - amd64
         include:
           - juju:
-              agent: 3.4.3  # renovate: juju-agent-pin-minor
+              agent: 3.4.5  # renovate: juju-agent-pin-minor
               allure_on_amd64: true
             architecture: arm64
           - juju: