Remove trailing newline from warning

Avoids rendering a literal '\n' in Auspice.

Author: victorlin

nextstrain_profiles/nextstrain-gisaid-21L/builds.yaml

@@ -19,7 +19,7 @@ slack_channel: "#ncov-gisaid-updates"
 
 genes: ["ORF1a", "ORF1b", "S", "ORF3a", "E", "M", "ORF6", "ORF7a", "ORF7b", "ORF8", "N", "ORF9b"]
 include_hcov19_prefix: True
-warning: >
+warning: >-
   On Oct 1, 2025, we received an email from GISAID stating that they will no
   longer be updating the flat file of EpiCoV data they've historically
   provisioned to Nextstrain since Feb 2020. Updates to these analyses are

nextstrain_profiles/nextstrain-gisaid/builds.yaml

@@ -18,7 +18,7 @@ slack_channel: "#ncov-gisaid-updates"
 
 genes: ["ORF1a", "ORF1b", "S", "ORF3a", "E", "M", "ORF6", "ORF7a", "ORF7b", "ORF8", "N", "ORF9b"]
 include_hcov19_prefix: True
-warning: >
+warning: >-
   On Oct 1, 2025, we received an email from GISAID stating that they will no
   longer be updating the flat file of EpiCoV data they've historically
   provisioned to Nextstrain since Feb 2020. Updates to these analyses are

nextstrain_profiles/nextstrain-open/builds.yaml

@@ -18,7 +18,7 @@ slack_channel: "#ncov-genbank-updates"
 
 genes: ["ORF1a", "ORF1b", "S", "ORF3a", "E", "M", "ORF6", "ORF7a", "ORF7b", "ORF8", "N", "ORF9b"]
 include_hcov19_prefix: False
-warning: >
+warning: >-
   This open (NCBI / GenBank) analysis is now our default view into SARS-CoV-2
   evolution. Previously we defaulted to GISAID-sourced data, however on October
   1st, 2025 GISAID indicated they will no longer update the flat file they