build(deps): bump icalendar from 5.0.13 to 6.0.0 in /tools/base

Bumps [icalendar](https://github.com/collective/icalendar) from 5.0.13 to 6.0.0.
- [Release notes](https://github.com/collective/icalendar/releases)
- [Changelog](https://github.com/collective/icalendar/blob/main/CHANGES.rst)
- [Commits](collective/icalendar@v5.0.13...v6.0.0)

---
updated-dependencies:
- dependency-name: icalendar
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

tools/base/requirements.txt

@@ -764,9 +764,9 @@ humanfriendly==10.0 \
     --hash=sha256:1697e1a8a8f550fd43c2865cd84542fc175a61dcb779b6fee18cf6b6ccba1477 \
     --hash=sha256:6b0b831ce8f15f7300721aa49829fc4e83921a9a301cc7f606be6686a2288ddc
     # via coloredlogs
-icalendar==5.0.13 \
-    --hash=sha256:5ded5415e2e1edef5ab230024a75878a7a81d518a3b1ae4f34bf20b173c84dc2 \
-    --hash=sha256:92799fde8cce0b61daa8383593836d1e19136e504fa1671f471f98be9b029706
+icalendar==6.0.0 \
+    --hash=sha256:567e718551d800362db04ca09777295336e1803f6fc6bc0a7a5e258917fa8ed0 \
+    --hash=sha256:7ddf60d343f3c1f716de9b62f6e80ffd95d03cab62464894a0539feab7b5c76e
     # via -r requirements.in
 idna==3.10 \
     --hash=sha256:12f65c9b470abda6dc35cf8e63cc574b1c52b11df2c86030af0ac09b01b13ea9 \
@@ -1179,7 +1179,6 @@ pytz==2024.2 \
     # via
     #   aio-core
     #   envoy-base-utils
-    #   icalendar
 pyu2f==0.1.5 \
     --hash=sha256:a3caa3a11842fc7d5746376f37195e6af5f17c0a15737538bb1cebf656fb306b
     # via google-reauth
@@ -1380,6 +1379,10 @@ typing-extensions==4.12.2 \
     --hash=sha256:04e5ca0351e0f3f85c6853954072df659d0d13fac324d0072316b67d7794700d \
     --hash=sha256:1a7ead55c7e559dd4dee8856e3a88b41225abfe1ce8df57b7c13915fe121ffb8
     # via pygithub
+tzdata==2024.2 \
+    --hash=sha256:7d85cc416e9382e69095b7bdf4afd9e3880418a2413feec7069d533d6b4e31cc \
+    --hash=sha256:a48093786cdcde33cad18c2555e8532f34422074448fbc874186f0abd79565cd
+    # via icalendar
 uritemplate==4.1.1 \
     --hash=sha256:4346edfc5c3b79f694bccd6d6099a322bbeb628dbf2cd86eea55a456ce5124f0 \
     --hash=sha256:830c08b8d99bdd312ea4ead05994a38e8936266f84b9a7878232db50b044e02e