website: Fix 'th' -> 'st' type in ISCA '23

Change-Id: I3da8dcb9ef96ecc93d11108b2198bd6a57a48d0a
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5-website/+/69138
Tested-by: Bobby Bruce <bbruce@ucdavis.edu>
Maintainer: Bobby Bruce <bbruce@ucdavis.edu>
Reviewed-by: Bobby Bruce <bbruce@ucdavis.edu>
diff --git a/_pages/events/isca-2023.md b/_pages/events/isca-2023.md
index 7101ae1..1cb2958 100644
--- a/_pages/events/isca-2023.md
+++ b/_pages/events/isca-2023.md
@@ -15,7 +15,7 @@
 
 * Submission deadline:  **April 14th 2023 (AOE)**
 * Notification of acceptance and time-slot awarded: **May 1st 2023**
-* ISCA dates: **June 17th to June 21th 2023**
+* ISCA dates: **June 17th to June 21st 2023**
 * Workshop date: **June 17th 2023**
 
 ## Call for Presentations
@@ -63,7 +63,7 @@
 
 * Submission deadline:  **April 14th 2023 (AOE)**
 * Notification of acceptance and time-slot awarded: **May 1st 2023**
-* ISCA dates: **June 17th to June 21th 2023**
+* ISCA dates: **June 17th to June 21st 2023**
 * Workshop date: **June 17th 2023**
 
 We look forward to receiving your proposals and seeing you at the gem5 Workshop!